Promax : Seismic Data Processing

Document Sample
Promax : Seismic Data Processing Powered By Docstoc
					             ProMAX 3D
        Seismic Processing and
               Analysis
                copyright © 1999 by Landmark Graphics Corporation




626072 Rev. C                                                       March 1999
                     Copyright © 1999 Landmark Graphics Corporation
                              All Rights Reserved Worldwide

This publication has been provided pursuant to an agreement containing restrictions on its use. The
publication is also protected by Federal copyright law. No part of this publication may be copied
or distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human
or computer language, in any form or by any means, electronic, magnetic, manual, or otherwise,
              or disclosed to third parties without the express written permission of:


                              Landmark Graphics Corporation
                       15150 Memorial Drive, Houston, TX 77079, U.S.A.
                                   Phone: 713-560-1000
                                    FAX: 713-560-1410




                                       Trademark Notices

Landmark, OpenWorks, SeisWorks, ZAP!, PetroWorks, and StratWorks are registered trademarks
                               of Landmark Graphics Corporation.
Pointing Dispatcher, Log Edit, Fast Track, SynTool, Contouring Assistant, TDQ, RAVE, 3DVI,
 SurfCube, SeisCube, VoxCube, Z-MAP Plus, ProMAX, ProMAX Prospector, ProMAX VSP,
                  MicroMAX, and Landmark Geo-dataWorks are trademarks
                               of Landmark Graphics Corporation.
          Technology for Teams is a service mark of Landmark Graphics Corporation.
                   ORACLE is a registered trademark of Oracle Corporation.
             IBM is a registered trademark of International Business Machines, Inc.
                            AIMS is a trademark of GX Technology.
           Motif, OSF, and OSF/Motif are trademarks of Open Software Corporation.
               UNIX is a registered trademark of UNIX System Laboratories, Inc.
     SPARC, SPARCstation, Sun, SunOs and NFS are trademarks of SUN Microsystems.
        X Window System is a trademark of the Massachusetts Institute of Technology.
                      SGI is a trademark of Silicon Graphics Incorporated.
  All other brand or product names are trademarks or registered trademarks of their respective
                                   companies or organizations.




                                               Note

The information contained in this document is subject to change without notice and should not be
construed as a commitment by Landmark Graphics Corporation. Landmark Graphics Corporation
assumes no responsibility for any error that may appear in this manual. Some states or jurisdictions
   do not allow disclaimer of expressed or implied warranties in certain transactions; therefore,
                               this statement may not apply to you.
                                                                                                         Contents

Agenda        . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-1

      Monday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-1
           Introductions, Course Outline, and Miscellaneous Topics . . . . . . . . . . . . . . .                                Agenda-1
           System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          Agenda-1
           ProMAX 3D Geometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                Agenda-1
               Discussion of 3D Tutorial Project. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                   Agenda-1
               Initial Look at the Trace Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .               Agenda-1
               Build 3D Database from Observers Notes . . . . . . . . . . . . . . . . . . . . . . . .                           Agenda-1
               Geometry Core Path Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                     Agenda-1
               ..........................................................                                                       Agenda-1

      Tuesday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-2
           Database From Geometry Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                      Agenda-2
           Processing Sequence Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .               Agenda-2
           Preprocessing and Elevation Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                  Agenda-2
           Superswath Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            Agenda-2
           3D Stack and Volume Comparison. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                      Agenda-2
           3D Stack Volume Displays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                Agenda-2

      Wednesday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-3
           3D Mix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   Agenda-3
           3D Stack Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             Agenda-3
           ProMAX Marine 3D Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                      Agenda-3
           Neural Net First Break Picking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                Agenda-3
           Source Receiver Geometry Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                     Agenda-3
           3D Refraction Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          Agenda-3
           Statistical Trace Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          Agenda-3

      Thursday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-4
           3D Residual Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-4
           Velocity Analysis and the Volume Viewer . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-4
           ProMAX Land Swath Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-4

      Friday . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-5
           3D Dip Moveout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Agenda-5


Landmark                                                    ProMAX 3D Seismic Processing and Analysis                                      i
Contents


                CDP Taper on Stack Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              Agenda-5
                3D Velocity Viewer/Editor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              Agenda-5
                Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   Agenda-5
                Land Geometry Using SPS Survey Data . . . . . . . . . . . . . . . . . . . . . . . . . . . .                         Agenda-5



Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
                                                                                                                          Preface-1
                     About The Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface-1
                     How To Use The Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface-1

          Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface-2
                     Mouse Button Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface-2
                     Exercise Organization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface-2

          Differences between 2D and 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preface-3
                     What makes 3D different from 2D in physical geometric terms? . . . . . . Preface-3
                     What is different in processing of 3D data relative to 2D? . . . . . . . . . . . Preface-3



System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                    1-1

          Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

          Directory Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
                     /ProMAX (or $PROMAX_HOME) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                       1-2
                     $PROMAX_HOME/sys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              1-2
                     $PROMAX_HOME/port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .               1-5
                     $PROMAX_HOME/etc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              1-5
                     $PROMAX_HOME/scratch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                1-5
                     $PROMAX_HOME/data (or $PROMAX_DATA_HOME) . . . . . . . . . . . . . . .                                              1-6

          Data Directories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

          Program Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
                     User Interface ($PROMAX_HOME/sys/bin/promax) . . . . . . . . . . . . . . . . . . . . 1-8
                     Super Executive Program (super_exec.exe) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
                     Executive Program (exec.exe) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
                     Processing Pipeline Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11
                     Types of Executive Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
                     Stand-Alone Processes and Socket Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14


ii              ProMAX 3D Seismic Processing and Analysis                                                                           Landmark
                                                                                                                               Contents


        Ordered Parameter Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
                  Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1-15
                  OPF Matrices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     1-16
                  Database Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       1-18
                  File Naming Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            1-19

        Parameter Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
                  Creating a Parameter Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
                  ASCII Import to a Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21
                  ASCII File Export from the Parameter Table Editor . . . . . . . . . . . . . . . . . . . . 1-22

        Disk Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
                  Secondary Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24

        Tape Datasets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26
                  Tape Trace Datasets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26

        Tape Catalog System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28
                  Tape Catalog Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28
                  Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28



ProMAX 3D Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
        Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

        ProMAX Geometry Assignment Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

        Loading Geometry Directly to Field Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

        Description of Manhattan 3d Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

        Observer’s Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

        First Look at the Trace Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

        3D Land Geometry Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
                  3D Land Geometry Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
                  Receivers Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10
                  Sources Spread Sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
                  Basemap QC and setting the Prospect Level Azimuth . . . . . . . . . . . . . . . . . . . 2-16


Landmark                                                   ProMAX 3D Seismic Processing and Analysis                                     iii
Contents


                 Patterns Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     2-18
                 Complete the Sources Spreadsheet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                2-19
                 CDP Binning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2-20
                 Interactive Spread QC using XYgraph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                  2-21
                 Defining the CDP binning grid. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             2-23
                 Interactive Grid Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        2-23
                 CDP Bin Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        2-28
                 QC Binning with Fold Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          2-29

       Final QC Plots from the Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31

       Load the Geometry to the SEGY Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33

       Graphical Geometry QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
                 Graphical Geometry QC Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35

       Geometry Core Path Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
                 How to Decide on the Primary Geometry Path . . . . . . . . . . . . . . . . . . . . . . . . 2-36
                 Transferring the Database to Trace Headers . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37

       Details of the Geometry Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
                 Steps Performed by Inline Geom Header Load . . . . . . . . . . . . . . . . . . . . . . . .                         2-38
                 Valid Trace Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .        2-39
                 Valid Trace Number Origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            2-40
                 Steps Performed By Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              2-40
                 Between Extraction and Geom Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                   2-41
                 Geometry Load Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             2-42

       Pre-Geometry Database Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
                 Pre Geometry Initialization flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
                 Complete the Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-46

       Inline Geom Header Load after Pre-Initialization . . . . . . . . . . . . . . . . . . . . . . 2-47
                 Load Geometry to Trace Headers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47



Database from Geometry Extraction . . . . . . . . . . . . . . . . . . . . . . . . . .                                                3-1

       Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

       Geometry Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2


iv         ProMAX 3D Seismic Processing and Analysis                                                                       Landmark
                                                                                                                          Contents


      Overview of the Exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
                Population after 2nd Half Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

      Read and Extract the First SEGY File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
                Create a New Line and Run the First Extraction . . . . . . . . . . . . . . . . . . . . . . . . 3-5

      Complete the Database for the First Half. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
                Land 3D Geometry Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
                QC the Input with a Basemap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
                Trace Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
                Automatic Bin Calculation and QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
                CDP Bin Origin and Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
                QC, Edit and Save the CDP Binning Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
                Reload the edited CDP Grid and Complete CDP Binning . . . . . . . . . . . . . . . . 3-23
                Finalize the Offset Binning and CDP Bin Direction Parameters . . . . . . . . . . . 3-24
                Generate a Fold QC Plot and Finalize the Database. . . . . . . . . . . . . . . . . . . . . 3-25

      Load Geometry to the Trace Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-27

      Append the Second SEGY File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29
                Run the Second Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29

      Complete the Database for the Second Half . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31
                Land 3D Geometry Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             3-31
                QC the Input with a Basemap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          3-32
                Trace Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   3-33
                Expand the CDP Binning Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            3-34
                Complete CDP Binning using the Batch CDP Binning Tool . . . . . . . . . . . . . .                                3-39

      Load Geometry to the Trace Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-42

      Exercise Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44

      Full Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45
                Create a New Line and Run the First Extraction . . . . . . . . . . . . . . . . . . . . . . . 3-45
                Edit the LIN Database. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47

      Processing without a Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-49
                Minimal Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-49




Landmark                                                ProMAX 3D Seismic Processing and Analysis                                  v
Contents


Processing Sequence Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                            4-1

        Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

        Main Process Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

        Detailed Process Flow - Trace Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

        Detailed Process Flow - DMO and Vel-Anal . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

        Detailed Process Flow - DMO Stack and Migration . . . . . . . . . . . . . . . . . . . . 4-5


Preprocessing and Elevation Statics                                                . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

        Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

        Top Mute and Decon Design Gate Picking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
                  Identifying Analysis Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
                  Pick a Top Mute and Miscellaneous Time Gate. . . . . . . . . . . . . . . . . . . . . . . . . 5-5

        Decon Test and Interactive Spectral Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
                  Build a Flow to look at a power spectrum before and after decon . . . . . . . . . . . 5-9

        Elevation Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
                  Apply Elevation Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      5-17
                  Datum Statics Calculation and Datum Statics Apply . . . . . . . . . . . . . . . . . . . .                        5-18
                  Datum Statics Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          5-18
                  Comparison of Smoothed Surfaces based on CDP Smoothing . . . . . . . . . . . .                                   5-21
                  Build and Execute a Flow to Compute the N-Datum . . . . . . . . . . . . . . . . . . . .                          5-21

        Superswath Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25

        Preprocessing Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
                  Build a Flow to Perform the Preprocessing on the First Half . . . . . . . . . . . . . 5-26
                  Label the Dataset and Output to Disk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
                  Build a Flow to Perform the Preprocessing on the Second Half . . . . . . . . . . . 5-28



3D Stack and Volume Comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                                            6-1



vi           ProMAX 3D Seismic Processing and Analysis                                                                     Landmark
                                                                                                                             Contents


       Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

       3D RMS Velocity Field ASCII Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

       3D Parameter Table Interpolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

       Picking a Post NMO Mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-10

       Stack 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15
                 Run Stack3D on the First Superswath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
                 Run Stack3D on the Other Superswath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18

       Merging the Partial Stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19
                 Alternative Stack Merge Method ------ DO NOT BUILD THIS FLOW . . . . . 6-21
                 The Subtraction option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21

       3D Stack Volume Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
                 Inline Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23
                 Crossline Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24
                 Time Slice Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26

       ProMAX 3D Viewer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-28

       3D Mix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-32
                 Apply a 3D Running Mix to the Initial Stack . . . . . . . . . . . . . . . . . . . . . . . . . . 6-32
                 Display the Mixed Stack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-33

       3D Stack Volume Comparison Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34

       3D Stack Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
                 Compare Inlines from Two Stack Volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
                 Compare Crosslines from Two Stack Volumes . . . . . . . . . . . . . . . . . . . . . . . . 6-39
                 Compare Time Slices from Two Stack Volumes . . . . . . . . . . . . . . . . . . . . . . . 6-42



Neural Net First Break Picking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
       Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

       Neural Network First Break Picking Overview . . . . . . . . . . . . . . . . . . . . . . . . . 7-2



Landmark                                                   ProMAX 3D Seismic Processing and Analysis                                  vii
Contents


         Neural Network FB Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

         Neural Network First Break Picking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
                   Using the First Break Pick Macro for QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13

         Importing First Break Picks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
                   ASCII Import of First Arrival Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14
                   QC the Imported Picks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15



Source Receiver Geometry Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                                           8-1

         Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

         Source Receiver Geometry Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
                   Example Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8-2
                   Offset Range from First Break Pick Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                 8-3
                   Offset Range from Trace Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              8-3
                   Database Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8-4
                   Analyze the Results using Simple Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                8-5
                   Analyze the Results using 3D Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .              8-5



Refraction Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                 9-1

         Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

         Refraction Statics Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2
                   Refraction Statics Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
                   3D Refraction Statics Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5
                   QC the Delay Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-6
                   3D Refraction Statics Inversion Parameterization . . . . . . . . . . . . . . . . . . . . . . . 9-9
                   3D Refraction Statics Computation Parameterization . . . . . . . . . . . . . . . . . . . 9-11

         Coordinate-based Refraction Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13

         Archive Original Elevation Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
                   Copy S_STATIC to ORGSSTAT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
                   Copy R_STATIC to ORGRSTAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-19




viii          ProMAX 3D Seismic Processing and Analysis                                                                     Landmark
                                                                                                                            Contents


         CDP Mean Static after Refraction Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-20
                   Datum Statics Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-20
                   Datum Statics Apply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-20

         Refraction Statics Apply and Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-21
                   ..............................................................                                                9-23
                   Apply NMO, post-NMO Trace Mute and Split the Flow. . . . . . . . . . . . . . . . .                            9-24
                   Stack the next of traces and output a refraction statics stack . . . . . . . . . . . . . .                    9-26
                   Run Stack3D on the Second Superswath . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                9-28

         Merging the Partial Stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-30


Statistical Trace Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
         Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

         Trace Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2

         Ensemble Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4

         Editing Data with Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5
                   Analyze the Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5

         Editing Data using Statistics with DBTools and IDA . . . . . . . . . . . . . . . . . . . 10-9
                   Start Trace Display and IDA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-10
                   Start DBTools and generate two displays. . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-10



3D Residual Statics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
         Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1

         F-XY Decon Model Building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-2

         Cross Correlation Gate Picking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
                   Procedure for Picking Statics Horizon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
                   Pick the Autostatics Correlation Gate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8

         Cross Correlation Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-10
                   Correlate the First Half . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-10


Landmark                                                   ProMAX 3D Seismic Processing and Analysis                                 ix
Contents


                QC the Picks from the First Half . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-11
                Correlate the Second Half. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12
                QC the Picks from the Second Half . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-13

       Merge the Two Halves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-14
                Merge the Two Attributes into a Single Continuous Set . . . . . . . . . . . . . . . . 11-14
                QC the merged values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-15

       External Model Autostatics Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-16
                Expand the Flow to Run the Xcor Sum Decomposition . . . . . . . . . . . . . . . . 11-17
                View the Results Using XDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-18

       Static Application and Comparison. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-19
                Apply the Residual Statics and Reproduce the Traces: . . . . . . . . . . . . . . . . .                    11-20
                Stack the First Half of the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    11-21
                Split the Flow and Output the Data for Velocity Analysis. . . . . . . . . . . . . . .                     11-22
                Run Stack3D on the Other Superswath . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             11-24

       Merging the Partial Stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-26

       Eigen Stack Model Building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-28
                Build the Eigen Stack External Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-29



Velocity Analysis and the Volume Viewer. . . . . . . . . . . . . . . . . . .                                                12-1

       Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

       Velocity Analysis Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2

       3D Supergather Generation and QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3
                Supergather Generation and Offset Distribution QC . . . . . . . . . . . . . . . . . . . . 12-4

       Precomputed Velocity Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-8
                Run the Precompute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-8
                Velocity Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-11
                Velocity Analysis Icons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-13
                Using the Volume Viewer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-13
                Velocity Analysis PD Tool: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-17




x          ProMAX 3D Seismic Processing and Analysis                                                                 Landmark
                                                                                                                         Contents


3D Dip Moveout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1
         Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-1

         Offset Binning Parameter QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-2
                   Offset Binning Parameter Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-2

         DMO to Gathers 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-9

         Parallel Processing Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-15

         System Administration for Parallel Processing . . . . . . . . . . . . . . . . . . . . . . . 13-17
                   PVM Daemon (Parallel Virtual Machine) . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-17
                   User environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-17

         Using DIPVELS for Zero Dip Velocity Estimation . . . . . . . . . . . . . . . . . . . 13-19

         DMO Stack 3D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-22
                   Run DMO to Stack3D with the rekill switch set to NO . . . . . . . . . . . . . . . . . 13-27
                   Compare the two DMO Stack Volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-28

         Trace Kill and Start Time Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-29
                   Reset Stack DMO Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-31



CDP Taper on Stack Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1
         Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-1

         CDP Taper Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-2

         CDP Taper flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-4

         Generating QC Plots of the Taper Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-6
                   QC Plots from XDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-6
                   Try other values for TOPTAPER and BOTTAPER . . . . . . . . . . . . . . . . . . . . . 14-6



3D Velocity Viewer/Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1
         Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1

Landmark                                                  ProMAX 3D Seismic Processing and Analysis                               xi
Contents


          3D Velocity Viewer/Editor Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2
                     Icon Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2
                     3D Table Triangulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3

          3D Velocity Viewer/Editor flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5
                     Select the 3D Velocity Viewer Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . .                         15-5
                     Edit and Smooth the RMS Velocity for FK Migration . . . . . . . . . . . . . . . . . .                                  15-6
                     Icon Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   15-6
                     Editing Velocities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       15-7
                     Velocity Field Gridding and Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                        15-8
                     Convert to Interval Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             15-9



Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .           16-1

          Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-1

          3D Migration Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-2
                     Stolt 3D Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .         16-3
                     Phase Shift Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          16-3
                     PSPC 3D Depth Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                16-3
                     Explicit FD 3D Time Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                  16-4
                     Explicit FD 3D Depth Migration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                   16-4

          Re-datum Velocities to Flat Datum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-5
                     Re-datum the Interval Velocities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-6

          3D Migration Exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16-7


ProMAX Marine 3D Geometry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .                                                  17-1

          Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-1

          3D Marine Geometry from UKOOA Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-2
                     Using the Marine 3D Geometry Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . 17-2
                     Determine Primary Azimuth for Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-5
                     Cable Feather QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-6
                     CDP Binning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-7
                     QC the Calculated Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-10


xii            ProMAX 3D Seismic Processing and Analysis                                                                           Landmark
                                                                                                                            Contents


                 Interactive Grid QC and Alteration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            17-12
                 Load Final Grid and Perform CDP Binning . . . . . . . . . . . . . . . . . . . . . . . . . .                    17-15
                 Critical Parameters During CDP Binning. . . . . . . . . . . . . . . . . . . . . . . . . . . .                  17-15
                 Receiver Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   17-19
                 QC the CDP Binned Data using a Fold Plot . . . . . . . . . . . . . . . . . . . . . . . . . .                   17-20
                 Finalize the Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    17-20

       Assigning CDP Flex Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-21
                 Inline and Crossline Overlap Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .             17-21
                 Inline and Crossline distance Weighting . . . . . . . . . . . . . . . . . . . . . . . . . . . .                17-23
                 Azimuth Weighting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .     17-23
                 Prime Line Weighting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .      17-24

       QC Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-26
                 Produce QC plots from the database. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-27
                 CDP Contribution and Null QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-28

       Expand Flex Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-29


ProMAX Land Swath Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-1
       Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-1

       3D Land Swath Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-2
                 Prepare the Line and run the Spreadsheet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-4
                 Receivers Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-4
                 Sources Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-7
                 Patterns Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-10
                 Complete the Sources Spreadsheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-12
                 Trace Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-12
                 Spread QC after Trace Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-15
                 Automatic Bin Calculation and QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-16
                 QC the Calculated Grid. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-18
                 Complete CDP Binning using Batch CDP Binning . . . . . . . . . . . . . . . . . . . . 18-21



Land Geometry Using SPS Survey Data. . . . . . . . . . . . . . . . . . . . . 19-1
       Topics covered in this chapter: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-1


Landmark                                                  ProMAX 3D Seismic Processing and Analysis                                  xiii
Contents


       3D Land Geometry from SPS Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-2
               Project Specifications: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-2
               Build Geometry from SPS files for Land 3D . . . . . . . . . . . . . . . . . . . . . . . . . . 19-4
               Setting Project Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-6
               Determine Primary Azimuth for Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-7
               Trace Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-7
               Spread QC after Trace Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-9
               Automatic Bin Calculation and QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-10
               QC the Calculated Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-12
               Complete CDP Binning using Batch CDP Binning . . . . . . . . . . . . . . . . . . . . 19-13




xiv        ProMAX 3D Seismic Processing and Analysis                                                                Landmark
                                                                         Agenda

Monday

Introductions, Course Outline, and Miscellaneous Topics

                      •   Differences between 2D and 3D
                      •   What makes 3D different from 2D in physical geometric terms?
                      •   What is different in processing 3D data relative to 2D?

System Overview

                      •   Directory Structure
                      •   Program Execution
                      •   Ordered Parameter Files
                      •   Parameter Tables
                      •   Disk Datasets
                      •   Tape Datasets

ProMAX 3D Geometry

      Discussion of 3D Tutorial Project

      Initial Look at the Trace Data

      Build 3D Database from Observers Notes
                      •   Input data into the spreadsheet
                      •   QC features within the spreadsheet/database
                      •   CDP Binning
                      •   Loading Geometry Directly to Field Data
                      •   Graphical Geometry QC

      Geometry Core Path Overview
                      •   Details of the Geometry Programs




Landmark                                            ProMAX 3D User Training Manual   Agenda-1
Agenda




Tuesday

Database From Geometry Extraction

                     •   Extraction of first half
                     •   Extraction of second half
                     •   Full Extraction
                     •   Processing without a Database

Processing Sequence Flow

Preprocessing and Elevation Statics

                     •   Top Mute and Decon Design Gate Picking
                     •   Decon Test and Interactive Spectral Analysis
                     •   Elevation Statics Computation
                     •   Pre-Processing Flow Execution

Superswath Definition

3D Stack and Volume Comparison

3D Stack Volume Displays

                     •   Inline Displays
                     •   Cross Line Displays
                     •   Time Slice Displays
                     •   ProMAX 3D Viewer




Agenda-2   ProMAX 3D User Training Manual                               Landmark
                                                                                      Agenda




Wednesday

3D Mix

                   •    Apply a 3D Running Mix to the Initial Stack

3D Stack Comparisons

                   •    Compare Inlines from Two Stack Volumes
                   •    Compare Crosslines from Two Stack Volumes
                   •    Compare Time Slices from Two Stack Volumes

ProMAX Marine 3D Geometry

Neural Net First Break Picking

Source Receiver Geometry Check

                   •    Use First Breaks to check shot and receiver coordinates

3D Refraction Statics

                   •    Compute Refraction Statics
                   •    Apply Refraction Statics

Statistical Trace Editing

                   •    Compute statistics about each trace and Ensemble Statistics
                   •    Edit traces based on the statistics
                   •    Edit data using Statistics with DBTools and IDA




Landmark                                        ProMAX 3D User Training Manual    Agenda-3
Agenda




Thursday

3D Residual Statics

                     •   F-XY Decon Model Building
                     •   Cross Correlation Gate Picking
                     •   Pick the Autostatics Correlation Gate
                     •   Cross Correlation Computation
                     •   External Model Autostatics Computation
                     •   Eigen Stack Model Building
                     •   Residual Static Application and Stack

Velocity Analysis and the Volume Viewer

                     •   Supergather Generation and Offset Distribution QC
                     •   Precomputed Velocity Analysis

ProMAX Land Swath Geometry

                     •   Simulated Multi-cable Swath shoot




Agenda-4   ProMAX 3D User Training Manual                                    Landmark
                                                                              Agenda




Friday

3D Dip Moveout

                  •   Offset Binning Parameter Determination
                  •   DMO to Gathers 3D
                  •   Parallel Processing Overview
                  •   DMO Stack 3D

CDP Taper on Stack Data

3D Velocity Viewer/Editor

                  •   Edit and Smooth the RMS Velocity for FK Migration
                  •   Velocity Field Gridding and Smoothing
                  •   Convert to Interval Velocity

Migration

                  •   Stolt 3D Migration
                  •   Phase Shift Migration
                  •   PSPC 3D Depth Migration
                  •   Explicit FD 3D Time Migration
                  •   Explicit FD 3D Depth Migration

Land Geometry Using SPS Survey Data




Landmark                                    ProMAX 3D User Training Manual   Agenda-5
Agenda




Agenda-6   ProMAX 3D User Training Manual   Landmark
                                                                           Preface
      About The Manual
                   This manual is intended to accompany the instruction given during the
                   standard ProMAX 3D User Training course. Because of the power and
                   flexibility of ProMAX 3D, it is unreasonable to attempt to cover all
                   possible features and applications in this manual. Instead, we try to
                   provide key examples and descriptions, using exercises which are
                   directed toward common uses of the system.

                   The manual is designed to be flexible for both you and the trainer.
                   Trainers can choose which topics, and in what order to present material
                   to best meet your needs. You will find it easy to use the manual as a
                   reference document for identifying a topic of interest and moving
                   directly into the associated exercise or reference.


      How To Use The Manual
                   This manual is divided into chapters that discuss the key aspects of the
                   ProMAX 3D system. In general, chapters conform to the following
                   outline:

                   •     Introduction: A brief discussion of the important points of the topic
                         and exercise(s) contained within the topic.

                   •     Topics Covered in Chapter: Brief list of skills or processes in the
                         order that they are covered in the exercise.

                   •     Topic Description: More detail about the individual skills or
                         processes covered in the chapter.

                   •     Exercise: Details pertaining to each skill in an exercise, along with
                         diagrams and explanations. Examples and diagrams will assist you
                         during the course by minimizing note taking requirements and
                         providing guidance through specific exercises.

                   This format allows you to glance at the topic description to either
                   quickly reference an implementation or simply as a means of refreshing
                   your memory on a previously covered topic. If you need more
                   information, see the Exercise sections of each topic.




Landmark                                ProMAX 3D Seismic Processing and Analysis    Preface-1
Preface




Conventions

          Mouse Button Help
                          This manual does not refer to using mouse buttons unless they are
                          specific to an operation. MB1 is used for most selections. The mouse
                          buttons are numbered from left to right so:

                          MB1 refers to an operation using the left mouse button. MB2 is the
                          middle mouse button. MB3 is the right mouse button.

                          Actions that can be applied to any mouse button include:

                          •   Click: Briefly depress the mouse button.

                          •   Double Click: Quickly depress the mouse button twice.

                          •   Shift-Click: Hold the shift key while depressing the mouse button.

                          •   Drag: Hold down the mouse button while moving the mouse.

                          Mouse buttons will not work properly if either Caps Lock or Nums Lock
                          are on.


          Exercise Organization
                          Each exercise consists of a series of steps that will build a flow, help
                          with parameter selection, execute the flow, and analyze the results.
                          Many of the steps give a detailed explanation of how to correctly pick
                          parameters or use the functionality of interactive processes.

                          The editing flow examples list key parameters for each process of the
                          exercise. As you progress through the exercises, familiar parameters
                          will not always be listed in the flow example.

                          The exercises are organized such that your dataset is used throughout
                          the training session. Carefully follow the instructor’s direction when
                          assigning geometry and checking the results of your flow. An
                          improperly generated dataset or database may cause a subsequent
                          exercise to fail.




Preface-2      ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                                                       Preface




Differences between 2D and 3D

      What makes 3D different from 2D in physical geometric terms?
                      •   3D surface geometry - spatial distribution of shots and receivers

                          multiple cables / higher number of traces/shot

                          variation in azimuth of CDP traces

                      •   Data volumes are generally much larger

                          tape to tape processing

                          more computational power


      What is different in processing of 3D data relative to 2D?
                      •   3D Subsurface Binning

                      •   3D Geometry QC procedures

                      •   3D Stack comparison techniques (header tricks)

                          inline - crossline - time slice plots

                      •   3D Refraction Statics --- program

                      •   3D Residual Statics

                          model building

                          correlation gate picking

                      •   3D Velocity Analysis

                      •   3D Velocity Viewer/Editor

                      •   3D Dip Velocity Analysis

                      •   3D DMO

                      •   3D Migration


Landmark                                 ProMAX 3D Seismic Processing and Analysis   Preface-3
Preface




Preface-4   ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                          Chapter 1
                                                  System Overview
In this chapter we discuss some of the behind-the-scenes system operation and the basic ProMAX
framework. Understanding the ProMAX framework and its relationship to the UNIX directory
structure can be useful, especially when processing large volumes.




Topics covered in this chapter:

                         t Directory Structure
                         t Program Execution
                         t Ordered Parameter Files
                         t Parameter Tables
                         t Disk Datasets
                         t Tape Datasets




Landmark                                   ProMAX 3D Seismic Processing and Analysis        1-1
Chapter 1: System Overview




Directory Structure

       /ProMAX (or $PROMAX_HOME)
                         The directory structure begins at a subdirectory set by the
                         $PROMAX_HOME environmental variable. This variable defaults to “/
                         advance”, and is used in all the following examples. Set the
                         $PROMAX_HOME environment variable to
                         /my_disk/my_world/ProMAX to have your ProMAX directory tree
                         begin below the /my_disk/my_world subdirectory.

                         All ProMAX development tools are included within the following
                         subdirectories: $PROMAX_HOME/sys/lib, $PROMAX_HOME/sys/
                         obj, $PROMAX_HOME/port/src, $PROMAX_HOME/port/bin,
                         $PROMAX_HOME/port/include and $PROMAX_HOME/port/man.


       $PROMAX_HOME/sys
                         Software that is Operating System Specific resides in
                         $PROMAX_HOME/sys which is actually a symbolic link to
                         subdirectories unique to a given hardware platform, such as:

                         $PROMAX_HOME/rs6000 for IBM RS6000 workstations,

                         $PROMAX_HOME/solaris for Sun Microsystems Sparcstations and
                         Cray 6400 workstations running Sun Solaris OS,

                         $PROMAX_HOME/sgimips for Silicon Graphics workstations using
                         the 32 bit operating system and

                         $PROMAX_HOME/sgimips4 for Silicon Graphics workstations using
                         the 64 bit operating system.

                         This link facilitates a single file server containing executable programs
                         and libraries for all machine types owned by a client. Machine specific
                         executables are invoked from the UNIX command line, located in
                         $PROMAX_HOME/sys/bin.

                         Operating System specific executables, called from ProMAX, are
                         located under $PROMAX_HOME/sys/exe. These machine-
                         dependent directories are named after machine type, not manufacturer,
                         to permit accommodation of different architectures from the same
                         vendor. Accommodating future hardware architectures will simply


1-2           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                         Chapter 1: System Overview


           involve addition of new subdirectories. Unlike menus, help and
           miscellaneous files, a single set of executables is capable of running all
           ProMAX products, provided the proper product specific license
           identification number is in place.

           Third party software distributed by ProMAX will now be distributed in
           a subdirectory of $PROMAX_HOME/sys/exe using the company’s
           name, thus avoiding conflicts where two vendors use identical file
           names. For example, SDI’s CGM Viewer software would be in
           $PROMAX_HOME/sys/exe/sdi and Frame Technology’s
           FrameViewer would be in $PROMAX_HOME/sys/exe/frame.




Landmark                     ProMAX 3D Seismic Processing and Analysis            1-3
Chapter 1: System Overview


                                ProMAX Directory Structure
      $PROMAX_HOME             /sys         /exe
       (default=.../ProMAX)                  exec.exe                     /frame
                                             super_exec.exe               /sdi
                                             *.exe from program           /3rd party
                                                                           software
                                           /bin
                                             *.exe from command line



                                           /lib
                                             lib*.a

                                           /plot
                               /port         /help                      /promax
                                                                         *.lok - Frame help
                                             /lib/X11/app-defaults       *.help -ASCII help
                                                Application window
                                                managers              /promax3d
                                                                      /promaxvsp
                                             /menu              /promax
                                                                  *.menu
                                                                  Processes
                                                               /promax3d
                                                               /promaxvsp
                                            /misc
                                                *_stat_math
                                                *.rgb-colormaps
                                                ProMax_defaults
                                            /bin
                                                start-up executable
                               /etc

                                  config_file
                                  product
                                  install.doc
                                  pvmhosts
                                  qconfig
                                  license.dat


                               /scratch

                               /queues

                               /data                      /area             /line
                              (or $PROMAX_DATA_HOME)




1-4           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                                Chapter 1: System Overview


      $PROMAX_HOME/port
                  Software that is Portable across all Platforms is grouped under a
                  single subdirectory $PROMAX_HOME/port. This includes:

                  menus and Processes ($PROMAX_HOME/port/menu),

                  helpfiles ($PROMAX_HOME/port/help),

                  miscellaneous files ($PROMAX_HOME/port/misc.)

                  Under the menu and help subdirectories are additional subdirectories for
                  each ProMAX software product. For instance, under
                  $PROMAX_HOME/port/menu, you will find subdirectories for
                  ProMAX 2D (promax), ProMAX 3D (ProMAX3D), and ProMAX VSP
                  (ProMAXVSP.) Menus for additional products are added as new
                  subdirectories under $PROMAX_HOME/port/menu. If your system
                  administrator is not afraid of the LISP programming language you can
                  have them customize the ProMAX menus and defaults.

                  The ...$PROMAX_HOME/port/bin contains the file “Promax” which is
                  the ProMAX start-up script. You may want to edit this file and
                  personalize it to your environment.

                  The ...$PROMAX_HOME/port/lib/X11/app-defaults contains the color
                  attributes and window configurations for the individual applications.


      $PROMAX_HOME/etc
                  Files unique to a particular machine are located in the
                  $PROMAX_HOME/etc subdirectory. Examples of such files are the
                  config_file, which contains peripheral setup information for all products
                  running on a particular machine, and the product file, which assigns
                  unique pathnames for various products located on the machine.


      $PROMAX_HOME/scratch
                  The scratch area defaults to $PROMAX_HOME/scratch. This location
                  can be overridden with the environmental variable,
                  PROMAX_SCRATCH_HOME.We recommend you point this to the
                  biggest file system you have write permission. The DMO, Migrations,
                  and Spreadsheets are heavy users of this file system. We also
                  recommend that you periodically clean this file system.




Landmark                            ProMAX 3D Seismic Processing and Analysis           1-5
Chapter 1: System Overview


       $PROMAX_HOME/data (or $PROMAX_DATA_HOME)
                         The primary data partition defaults to $PROMAX_HOME/data, with
                         new areas being added as subdirectories beneath this subdirectory. This
                         default location is specified using the entry:

                             — primary disk storage partition: $PROMAX_HOME/data 200

                         in the $PROMAX_HOME/etc/config_file. This location can also be set
                         with the environmental variable $PROMAX_DATA_HOME.We also
                         recommend that you point this to a large files system you can write to




1-6           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                                     Chapter 1: System Overview




Data Directories

                       Each region identifies a collection of files and directories which can be
                       summarized as the Area and Line separated into four main file types: 1)
                       Parameter Tables, 2) Trace/Trace Headers, 3) Flows, and 4) Ordered
                       Parameter Files database.

           PROMAX_DATA_HOME
           or
           /Data

                   /Area
                                  Area subdirectory
                   DescName
                                  and its files
                   Project
                        /Line
                        DescName
                        17968042TVEL
                        31790267TGAT              1) Parameter Table files
                        36247238TMUT
                        12345678CIND             Index and Map Dataset files
                        12345678CMAP
                                /12345678
                                HDR1                 2) Dataset subdirectory
                                HDR2                 and Header and Trace
                                TRC1                 Dataset files
                                TRC2

                                /Flow1
                                DescName
                                                     3) A Flow subdirectory
                                TypeName
                                                     and its files
                                job.output
                                packet.job

                                                              4) /OPF.SIN Database
                                /OPF.SIN                      subdirectory and
                                OPF60_SIN.GEOMETRY.ELEV       a non-spanned file

                                                                   /OPF.SRF Database
                                /OPF.SRF                           subdirectory and a
                                #s0_OPF60_SRF.GEOMETRY.ELEV        span file




Landmark                                 ProMAX 3D Seismic Processing and Analysis           1-7
Chapter 1: System Overview




Program Execution

       User Interface ($PROMAX_HOME/sys/bin/promax)
                         Interaction with ProMAX is handled through the User Interface. As you
                         categorize your data into Areas and Lines, the User Interface
                         automatically creates the necessary UNIX subdirectories and provides
                         an easy means of traversing this data structure.

                         However, the primary function of the User Interface is to create, modify,
                         and execute processing flows. A flow is a sequence of processes that you
                         perform on seismic data. Flows are built by selecting processes from a
                         list, and then selecting parameters for each process. A typical flow
                         contains an input process, one or more data manipulation processes, and
                         a display and/or output process. All information, needed to execute a
                         flow, is held within a Packet File (packet.job) within each Flow
                         subdirectory. This Packet File provides the primary means of
                         communication between the User Interface and the Super Executive
                         program. See next section, Super Executive Program.

                         In addition, the User Interface provides utility functions for:

                         •   copying, deleting and archiving Areas, Lines, Flows, and seismic
                             datasets

                         •   accessing and manipulating ordered database files and parameter
                             tables

                         •   displaying processing histories for your flows

                         •   providing information about currently running jobs

                         The User Interface is primarily mouse-driven and provides point-and-
                         click access to the functions.




1-8           ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                                 Chapter 1: System Overview


                    .




                                             Program Execution


      Super Executive Program (super_exec.exe)
                    Execution of a flow is handled by the Super Executive, which is
                    launched as a separate task by the User Interface. The Super Executive
                    is a high level driver program that examines processes in your flow by
                    reading packet.job and determines which executables to use. The
                    majority of the processes are subroutines linked together to form the
                    Executive. Since this is the processing kernel for ProMAX, many of
                    your processing flows, although they contain several processes, are
                    handled by a single execution of the Executive. Several of the processes
                    are stand-alone programs. These processes cannot operate under the


Landmark                             ProMAX 3D Seismic Processing and Analysis           1-9
Chapter 1: System Overview


                         control of the Executive, and handle their own data input and output by
                         directly accessing external datasets. In these instances, the Super
                         Executive is responsible for invoking the stand-alone programs and, if
                         necessary, multiple calls to the Executive in the proper sequence.

                         The Packet File, packet.job, defines the processes and their type for
                         execution. The Super Executive concerns itself with only two types of
                         processes:

                         •   Executive processes

                         •   Stand-alone processes

                         Executive processes are actually subroutines operating in a pipeline,
                         meaning they accept input data and write output data at the driver level.
                         However, stand-alone processes cannot be executed within a pipeline,
                         but rather must obtain input and/or produce output by directly accessing
                         external datasets.

                         The Super Executive sequentially gathers all Executive-type processes
                         until a stand-alone is encountered. At that point, the Packet File
                         information for the Executive processes is passed to the Executive
                         routine (exec.exe) for processing. Once this is completed, the Super
                         Executive invokes the stand-alone program for processing, and then
                         another group of Executive processes, or another stand-alone process.
                         This continues until all processes in the flow have been completed.


       Executive Program (exec.exe)
                         The Executive program is the primary processing executable for
                         ProMAX. The majority of the processes available under ProMAX are
                         contained in this one executable program.

                         The Executive features a pipeline architecture that allows multiple
                         seismic processes to operate on the data before it is displayed or written
                         to a dataset. Special processes, known as input and output tools, handle
                         the tasks of reading and writing the seismic data, removing this
                         burdensome task from the individual processes. This results in processes
                         that are easier to develop and maintain. The basic flow of data through
                         the Executive pipeline is shown below:




1-10          ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                                   Chapter 1: System Overview


      Processing Pipeline Diagram




           Disk Data
           Input                 AGC
                                                               Trace Display
                                         F-K Filter




                                     Socket
                                     Tool
                                                                      Disk Data Output




                                   Processing Pipeline

                       Each individual process will not operate until it has accumulated the
                       necessary traces. Single trace processes will run on each trace as the
                       traces come down the pipe. Multi channel processes will wait until an
                       entire ensemble is available. For example in the example flow the FK


Landmark                                ProMAX 3D Seismic Processing and Analysis         1-11
Chapter 1: System Overview


                         filter will not run until one ensemble of traces has passed through the
                         DDI and AGC. If we specify for the Trace Display to display 2
                         ensembles, it will not make a display until two shots have been
                         processed through the DDI, AGC and FK filter. No additional traces
                         will be processed until Trace Display is instructed to release the traces
                         that it has displayed and is holding in memory by clicking on the traffic
                         light icon or terminating its execution (but continuing the flow).

                         Note: All the processes shown are Executive processes and thus operate
                         in the pipeline. An intermediate dataset and an additional input tool
                         process is needed if a stand-alone process were included in this flow.

                         A pipeline process must accept seismic traces from the Executive,
                         process them, and return the processed data to the Executive.




1-12          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                                 Chapter 1: System Overview




                                              Disk Data Input, Tape Data
                                              Input and standalone tools
                                              always start new pipes
                                              within a single flow


                  Disk Data
                  Input                   AGC


                                                  F-K Filter




                                                               Decon


    Disk Data
    Input
                                                                          Disk Data
                                                                          Output
                NMO



                 CDP Stack




                              Bandpass
                              Filter


                                         Disk Data
                                         Output
       One pipe must complete
       successfully before a new
       pipe will start processing




                              Multiple Pipes in One Flow



Landmark                              ProMAX 3D Seismic Processing and Analysis       1-13
Chapter 1: System Overview


       Types of Executive Processes
                          The table below describes the four types of processes defined for use in
                          the Executive.

                                       Table 1: ProMAX Executive Process Types
                      Process Type           Description

                      simple tools           Accepts and returns a single seismic trace.

                      ensemble tools         Accepts and returns a gather of seismic traces

                      complex tools          Accepts and returns a variable number of seismic traces such
                                             as, stack. This type of process actually controls the flow of
                                             seismic data.

                      panel tools            Accepts and returns overlapping panels of traces to
                                             accommodate a group of traces too large to fit into memory.
                                             Overlapping panels are processed and then merged along
                                             their seams.



       Stand-Alone Processes and Socket Tools
                          Some seismic processing tools are not well suited to a pipeline
                          architecture. Typically, these are tools making multiple passes through
                          the data or requiring self-directed input. These tools can be run inline in
                          a ProMAX job flow and appear as ordinary tools, but in reality are
                          launched as separate processes. The current version of ProMAX does
                          not provide the ability to output datasets from a stand-alone process.

                          InterProcess Communication tools start a new process and then
                          communicates with the Executive via UNIX interprocess
                          communications. InterProcess Communication tools have the singular
                          advantage of being able to accept and output traces in an asynchronous
                          manner.




1-14          ProMAX 3D Seismic Processing and Analysis                                         Landmark
                                                                              Chapter 1: System Overview




Ordered Parameter Files
Click to jump to the section
                               This section discusses the following issues relating to the Ordered
                               Parameter Files database:

                               •   Organization

                               •   Database Structure

                               •   File Naming Conventions

                               The Ordered Parameter Files database serves as a central repository of
                               information that you or the various tools can rapidly access.
                               Collectively, the ordered database files store large classes of data,
                               including acquisition parameters, geometry, statics and other surface
                               consistent information, and pointers between the source, receiver and
                               CDP domains. The design of the Orders is tailored for seismic data, and
                               provides a compact format without duplication of information.

                               The Ordered Parameter Files database is primarily used to obtain a list
                               of traces to process, such as traces for a shot or CDP. This list of traces
                               is then used to locate the index to actual trace data and headers in the
                               MAP file of the dataset. Once determined, the index is used to extract
                               the trace and trace header data from their files.


            Organization
                               The Ordered Parameter Files contain information applying to a line and
                               its datasets. For this reason, there can be many datasets for a single set
                               of Ordered Database Files.

                               Ordered Parameter Files, unique to a line, reside in the Area/Line
                               subdirectory. The Ordered Parameter Files database stores information
                               in structured categories, known as Orders, representing unique sets of
                               information. In each Order, there are N slots available for storage of
                               information, where N is the number of elements in the order, such as the
                               number of sources, number of surface locations, or number of CDPs.
                               Each slot contains various attributes in various formats for one




Landmark                                          ProMAX 3D Seismic Processing and Analysis           1-15
Chapter 1: System Overview


                         particular element of the Order. The Orders are organized as shown in
                         the table below.

                                    Table 2: Organization of Ordered Parameter Files
                       LIN (Line)           Contains constant line information, such as final datum, type of
                                            units, source type, total number of shots.

                       TRC (Trace)          Contains information varying by trace, such as FB Picks, trim
                                            statics, source-receiver offsets.

                       SRF                  Contains information varying by surface receiver location, such
                       (Surface location)   as surface location x,y coordinates, surface location elevations,
                                            surface location statics, number of traces received at each
                                            surface location, and receiver fold.

                       SIN                  Contains information varying by source point, such as source
                       (Source Index #)     x,y coordinates, source elevations, source uphole times, nearest
                                            surface location to source, source statics.

                       CDP (Common          Contains information varying by CDP location, such as CDP x,y
                       Depth Point)         coordinates, CDP elevation, CDP fold, nearest surface location.

                       CHN (Channel)        Contains information varying by channel number, such as
                                            Channel gain constants, channel statics

                       OFB                  Contains information varying by offset bin number, such as
                       (Offset Bin)         surface consistent amplitude analysis. OFB is created when
                                            certain processes are run, such as surface consistent amplitude
                                            analysis.

                       PAT (Pattern)        Contains information describing the recording patterns.



                                       Table 3: Additional Parameter Files for 3D
                       ILN (Inline)         Contains information, constant within a 3D inline.(Number of
                                            traces per line)

                       XLN (Crossline)      Contains information constant within a 3D crossline. (Number
                                            of traces per crossline)



       OPF Matrices
                         The OPF database files can be considered to be matrices.

                         Each OPF is indexed against the OPF counter and there are various
                         single numbers per index. Note the relative size of the TRC OPF to the
                         other OPF files. The TRC is by far the largest contributor to the size of
                         the database on disk



1-16          ProMAX 3D Seismic Processing and Analysis                                            Landmark
                                               Chapter 1: System Overview




             SIN (Sources) Database




           SRF (Receivers) Database


                   OPF Matrices




Landmark             ProMAX 3D Seismic Processing and Analysis      1-17
Chapter 1: System Overview


       Database Structure
                         The ProMAX database was restructured for the 6.0 release to handle
                         large 3D land and marine surveys. The features of the new database
                         structure are listed below:

                         Each order is contained within a subdirectory under Area and Line. For
                         example, the TRC is in the subdirectory OPF.TRC.

                         There are two types of files contained in the OPF subdirectories:

                         •   Parameter: Contain attribute values. There may be any number of
                             attribute files associated with an OPF.

                         •   Index: Holds the list of parameters and their formats. There is only
                             one index file in each OPF subdirectory. The exception to this is the
                             LIN OPF. The LIN information is managed by just two files, one
                             index and one parameter, named LIN.NDX and LIN.REC.

                         OPF files are of two types:

                         •   Span: These files are denoted by the prefix, #s. Non-span files lack
                             this prefix. The TRC, CDP, SIN, and SRF OPF parameters are span
                             files. The first span of 10MB for each parameter file is always
                             written to primary storage. Span files are created in the secondary
                             storage partitions listed in the config_file as denoted with the OPF
                             keyword. Span files may be moved to any disk partition within the
                             secondary storage list for read purposes. Newly created spans are
                             written in the OPF denoted secondary storage partitions. All
                             subsequent spans are written to the secondary storage partitions
                             denoted by the OPF keyword in a round robin fashion until the
                             secondary storage is full. Then, subsequent spans are created in
                             primary storage. Span file size is currently fixed at 10 megabytes, or
                             approximately 2.5 million 4 byte values per span file.

                         •   Non-span: All other OPFs are non-span.

                         Given the fact that each parameter is managed by a file, it may be
                         necessary to increase the “maximum number of files open” limit on
                         some systems, specifically, SUN, Solaris and SGI. From the csh, the
                         following command increases the file limit to 255 files open, “limit de
                         255”.

                         The geometry spreadsheet is a ProMAX database editor. Modifying
                         information within a spreadsheet editor and saving the changes will
                         automatically update the database. There is no longer an import or



1-18          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                                        Chapter 1: System Overview


                    export from the geometry database to the ProMAX database files as was
                    required prior to the 6.0 release.

                    Database append is allowed. Data can be added to the database via the
                    OPF Extract tool or the geometry spreadsheet. This allows for the
                    database to be constructed incrementally as the data arrives.

                    There is improved network access to the database. Database I/O across
                    the network is optimized to an NFS default packet size of 4K. All
                    database reads and writes are in 4K pages.

                    Existing and restored 5.X databases are automatically converted to the
                    6.0 (and later) database format.


      File Naming Conventions
                    Parameter file names consist of information type and parameter name,
                    preceded by a prefix denoting the Order of the parameter.

                    For example, the x coordinate for a shot in the SIN has the following
                    name: #s0_OPF60_SIN.GEOMETRY.X_COORD. Where #s0_OPF60
                    indicates a first span file for the parameter, _SIN denotes the Order,
                    GEOMETRY describes the information type of the parameter, and
                    X_COORD is the parameter name.

                    Index file names contain the three letter Order name. For example, the
                    index file for the TRC is called OPF60_TRC.

                     NOTE:

                     The index file for each Order must remain in the primary storage partition. Span
                     parameter files may be moved and distributed anywhere within primary and
                     secondary storage.



                    Within each Order, there are often multiple attributes, with each
                    attribute being given a unique name.




Landmark                                ProMAX 3D Seismic Processing and Analysis                 1-19
Chapter 1: System Overview




Parameter Tables

                         Parameter Tables are files used to store lists of information in a very
                         generalized structure. To increase access speed and reduce storage
                         requirements, parameter tables are stored in binary format. They are
                         stored in the Area/Line subdirectory along with seismic datasets, the
                         Ordered Parameter Files database files (those not in separate
                         directories), and Flow subdirectories.

                         Parameter Tables are often referred to as part of the database. Parameter
                         tables differ from the OPF database in OPF files contain many attributes
                         that are 1 number per something. Parameter tables contain more than
                         one number per something. For example a velocity function contains
                         multiple velocity-time pairs at one CDP.


       Creating a Parameter Table
                         Parameter tables are typically created in three ways:

                         •   Processes store parameters to a table for later use by other
                             processes.

                         •   Parameter tables can be imported from ASCII files that were
                             created by other software packages or hand-edited by you.

                         •   Parameter tables can be created by hand using the Parameter Table
                             Editor which is opened by the Create option on the parameter table
                             list screen.

                         An example is the interactive picking of time gates within the Trace
                         Display process. After seismic data is displayed on the screen, you pull
                         down the Picking Menu and choose the type of table to create. The end
                         result of your work is a parameter table. If you were to pick a top mute,
                         you would generate a parameter table ending in TMUT. If you were
                         picking a time horizon, you would generate a table ending in THOR.
                         These picks are stored in tabular format, where they can be edited, used




1-20          ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                                         Chapter 1: System Overview


                     by other processes in later processing, or exported to ASCII files for use
                     by other software packages.s

                      WARNING:

                      Remember, you name and store the parameter tables in their specific Area/Line
                      subdirectory. Therefore, you can inadvertently overwrite an existing parameter
                      table by editing a parameter table in a different processing flow.



      ASCII Import to a Parameter Table
                     File Import reads either ASCII or EBCDIC formatted files with fixed
                     columnar data into the spreadsheet editor.

                     When the application is initialized, two windows appear: the main
                     ASCII/EBCDIC File Import window and the File Import Selection
                     dialog. After a file has been selected, it is displayed, and you can select
                     rows. Note: Filter and Apply appear grayed out and are insensitive to
                     mouse button actions. After Format has been pressed and a columnar
                     format selected, Filter and Apply appear normally and are available for
                     use. The steps involved in performing a file import are as follows:

                     1. Select File: Select a file to import. If the text file does not contain
                        valid line terminators, use Width to set the line width and then re-
                        read the file.

                     1. Select Format: Select a previous format or create a new format.

                     1. Review or Edit Column Definitions: Review the previously defined
                        columns in an existing format by selecting all the columns. Review
                        the highlighted regions in the file display for accuracy. Columns
                        can either be edited by hand entering Start Col. and End Col.
                        values, or by performing click and drag column definition.

                     1. Save the Column Definition: Save any changes to the current
                        column definition to disk for later retrieval.

                     1. Filter the File for Invalid Text: Search the marked columns and
                        rows for any invalid text. Text may be excluded or replaced within
                        this interactive operation.

                     1. Perform the Import: Select the Apply button. The application
                        windows will close and the focus will return to the calling
                        spreadsheet.




Landmark                                 ProMAX 3D Seismic Processing and Analysis                 1-21
Chapter 1: System Overview


       ASCII File Export from the Parameter Table Editor
                         Export writes either ASCII or EBCDIC formatted files with fixed
                         columnar data from a spreadsheet editor.

                         When the application is initialized, the main ASCII File Export window
                         will appear. After a file and format has been selected, then the ASCII
                         text is displayed and the Apply button is activated. The steps involved
                         in performing a file export are as follows:

                         1. Select File: Select a file for export within the File Export Selection
                            dialog.

                         1. Select Format: Select a previous format or create a new format.

                         1. Review or Edit Column Definitions: Review the previously defined
                            columns in an existing format by selecting all the columns. Review
                            the highlighted regions in the file display for accuracy. Columns
                            can either be edited by hand entering Start Col. and End Col.
                            values, or by performing click and drag column definition.

                         1. Save the Column Definition: Save any changes to the current
                            column definition to disk for later retrieval.

                         1. Perform the Export: Select the Apply button.

                         1. Cancel the Export Operation: Press the Cancel button to close the
                            export windows and return to the calling spreadsheet.




1-22          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                                    Chapter 1: System Overview




Disk Datasets

                ProMAX uses a proprietary disk dataset format that is tailored for
                interactive processing and random disk access. Disk dataset files can
                span multiple filesystems, allowing for unlimited filesize datasets.

                A typical set of files might look like this:

                    — $PROMAX_HOME/data/usertutorials/landexample/
                      12345678CIND
                      $PROMAX_HOME/data/usertutorials/landexample/
                      12345678CMAP
                      $PROMAX_HOME/data/usertutorials/landexample/12345678/
                      TRC1
                      $PROMAX_HOME/data/usertutorials/landexample/12345678/
                      HDR1

                These files are described in more detail in the table below.

                               Table 4: Composition of a Seismic Dataset
                File Name           Contents
                Trace               File containing actual sample values for data trace.
                (...TRCx)

                Trace Header        File containing trace header entries corresponding to data
                (....HDRx)          samples for traces in the trace file. This file may vary in
                                    length, growing as new header entries are added. Keep trace
                                    headers in a separate file so trace headers can be sorted
                                    without needing to skip past the seismic data samples.

                Map                 File keeps track of trace locations, even if data flows over
                (....CMAP)          many disks. Given a particular trace number, it will find the
                                    sequential trace number within the dataset. This rapidly
                                    accesses traces during processing. The map file is a separate
                                    file, as it may grow during processing, it is always held in the
                                    line directory.

                Index               File has free-form format information relating to the entire
                (....CIND)          dataset, including sample interval, number of samples per
                                    trace, processing history, and names of trace header entries.
                                    This file may grow during processing, and it is also always
                                    held in the line directory.




Landmark                           ProMAX 3D Seismic Processing and Analysis                    1-23
Chapter 1: System Overview




                                      CIND                          HDRx




                                      CMAP                            TRCx




                                      Disk Dataset Components - Relative Sizes


       Secondary Storage
                         In a default ProMAX configuration, all seismic dataset files reside on a
                         single disk partition. The location of this disk partition is set in the
                         $PROMAX_HOME/etc/config_file with the entry:

                             — primary disk storage partition: $PROMAX_HOME/promax/
                               data 200

                         In addition to the actual trace data files, the primary storage partition
                         will always contain your flow subdirectories, parameter tables, ordered
                         parameter files, and various miscellaneous files. The ...CIND and
                         ...CMAP files which comprise an integral part of any seismic dataset are
                         always written to primary storage.

                         Since the primary storage file system is of finite size, ProMAX provides
                         the capability to have some of the disk datasets, such as the ...TRCx and
                         ...HDRx files, and some of the ordered parameter files span multiple
                         disk partitions. Disk partitions other than the primary disk storage
                         partition are referred to as secondary storage.

                         All secondary storage disk partitions must be declared in the appropriate
                         $PROMAX_HOME/etc/config_file. Samples entries are:



1-24          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                                          Chapter 1: System Overview


                     secondary disk storage partition: $PROMAX_HOME/data2 20 TRC
                     OPF
                     secondary disk storage partition: $PROMAX_HOME/data3 20 TRC
                     secondary disk storage partition: $PROMAX_HOME/data4 20 OPF
                     secondary disk storage partition: $PROMAX_HOME/data5 20


           Primary      Secondary            Secondary             Secondary           Secondary

           Data            Data2                Data3                Data4               Data5




                     Refer to the ProMAX System Administration guide for a complete
                     description of the config_file entries for primary and secondary disk
                     storage. 20 is the default disk file size in Megabytes. This default is
                     probably too small for modern surveys as it was based on the old Unix
                     2Gig file system limitation. A better value would be 4000, or as large as
                     your dataset, or as large as a file as your system will allow.

                      WARNING:

                      If the Primary file system fills up ProMAX will crash and will not be able to launch
                      until space on Primary has been cleaned up.



                     Under the default configuration, the initial TRC1 and HDR1 files are
                     written to the primary storage partition. It is possible to override this
                     behavior by setting the appropriate parameter in Disk Data Output. If the
                     parameter Skip primary disk partition? is set to Yes, then no TRC or
                     HDR files will be written to the primary disk partition. This can be
                     useful as a means of maintaining space on the primary storage partition.
                     (To make this the default situation for all users, have your ProMAX
                     system administrator edit the diskwrite.menu file, setting the value for
                     Alstore to ‘t’ instead of ‘nil’).

                     Secondary storage is used in a “as listed and available” fashion. As an
                     attempt to minimize data loss due to disk hardware failure, ProMAX
                     tries to write a dataset to as few physical disks as possible. If the primary
                     storage partition is skipped by setting the appropriate parameter in Disk
                     Data Output, the CIND and CMAP files are still written to the primary
                     storage partition, but the TRCx or HDRx files will not be found there.




Landmark                                 ProMAX 3D Seismic Processing and Analysis                  1-25
Chapter 1: System Overview




Tape Datasets

                         Tape datasets are stored in a proprietary format, similar to the disk
                         dataset format, but incorporating required structures for tape input and
                         output. Tape input/output operates either in conjunction with a tape
                         catalog system, or without reference to the tape catalog. The tape
                         devices used for the Tape Data Input, Tape Data Insert, and Tape Data
                         Output processes are declared in the ProMAX device configuration
                         window. This allows access to tape drives anywhere on a network. The
                         machines that the tape drives are attached to do not need to be licensed
                         for ProMAX, but the fclient.exe program must be installed.


       Tape Trace Datasets
                         A ProMAX tape dataset is similar to a disk dataset in that the index file
                         (...CIND) and map file (...CMAP) still reside on disk in the Line/survey
                         database. Refer to the documentation in the Disk Datasets portion of this
                         helpfile for a discussion of these files. Having the index and map files
                         available on disk provides you with immediate access to information
                         about the dataset, without needing to access any tapes. It also provides
                         all the information necessary to access traces in a non-sequential
                         manner.

                         Although the index and map files still reside on disk, copies of them are
                         also placed on tape(s), so that the tape(s) can serve as a self-contained
                         unit(s). If the index and map files are removed from disk, or never
                         existed, as in the case where a dataset is shipped to another site, the tapes
                         can be read without them. However, access to datasets through the index
                         and map files residing solely on tape must be purely sequential.

                         Tape datasets are written by the Tape Data Output process, and can be
                         read using the Tape Data Input or Tape Data Insert processes. These
                         input processes include the capability to input tapes by reel, ensemble
                         number, or trace number. Refer to the relevant helpfile for a complete
                         description of the parameters used in these processes.

                         The use or non-use of the tape catalog in conjunction with the tape I/O
                         processes is determined by the tape catalog type entry in the appropriate
                         $PROMAX_HOME/etc/config_file. Setting this variable to full
                         activates catalog access, while an entry of none deactivates catalog
                         access. An entry of external is used to indicate that an external tape
                         catalog, such as the Cray Reel Librarian, will be used. You can override
                         the setting provided in the config_file by setting the environment


1-26          ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                         Chapter 1: System Overview


           variable for BYPASS_CATALOG to ‘t’, in which case the catalog will
           not be used. The actual tape devices to use for tape I/O must also appear
           as entries in the config_file, under the tape device: stanza.




Landmark                     ProMAX 3D Seismic Processing and Analysis          1-27
Chapter 1: System Overview




Tape Catalog System

       Tape Catalog Overview
                         The fundamental strategy of the tape catalog is that a group of tapes are
                         introduced or logged into the tape catalog, which then works in
                         conjunction with the Tape Input, Tape Insert, and Tape Output
                         processes to provide access to those tapes from within the ProMAX
                         system. Before being introduced to the catalog, an ANSI label is written
                         to each tape using the catalog utilities outlined below. The catalog
                         system knows the label and status (initially SCRATCH) of every tape,
                         and can monitor and validate the tape catalog resources accordingly. For
                         example, when a request for an output dataset is made, the catalog can
                         decide which tape to use, and can verify that the correct tape is mounted.
                         When a dataset overflows a tape, the catalog can decide which tape to
                         use next, and can again verify that the correct tape is mounted. When a
                         request for an input dataset is made, the catalog knows which tapes
                         belong to the dataset, and can verify that the correct tapes are mounted
                         in the correct order.


       Getting Started
                         The first step in using the ProMAX tape catalog is to create some labeled
                         tapes.

                         The program $PROMAX_HOME/sys/bin/tcat is used for tape labelling,
                         catalog creation and maintenance, and for listing current catalog
                         information. The program is run from the UNIX command line.

                         The following steps are required to successfully access the tape catalog:

                         1. Label tapes

                         1. Read and Display tape labels

                         1. Add labeled tapes to a totally new catalog

                         Before adding the tapes to a new catalog, it is a good idea to visually
                         inspect the contents of the label information file for duplicate or missing
                         entries. The contents typically look like:

                         0 AAAAAA 0 1 4
                         1 AAAAAB 0 1 4


1-28          ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                        Chapter 1: System Overview


           2 AAAAAC 0 1 4
           3 AAAAAD 0 1 4
           4 AAAAAE 0 1 4

           The fields are: volume serial number (digital form), volume serial
           number (character form), tape rack slot number, site number, and media
           type, respectively. You can manually edit these fields.

           1. Write a label information file from the existing catalog.

           1. Add labeled tapes (and datasets) to the existing catalog.

           1. Merge an additional catalog into the existing catalog.

           1. Delete a dataset from the catalog.




Landmark                    ProMAX 3D Seismic Processing and Analysis        1-29
Chapter 1: System Overview




1-30          ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                              Chapter 2
                                       ProMAX 3D Geometry
Geometry Assignment is designed to create the standard Ordered Parameter File directories,
OPFs, and load standard ProMAX geometry information into the trace headers. The sequence of
steps depends upon available information. This chapter serves as an introduction to different
approaches of geometry assignment. The Geometry Overview section in the Reference Manual
and online helpfile provide further details of the geometry assignment process.

In this chapter we will present one of the three different methods for building a ProMAX
database. This method is referred to as the “From Survey” method where the database is built
from observers log and ASCII survey file information. After the database is complete the
geometry information is copied to the trace headers of the input seismic data on the first read from
the field tapes.




Topics covered in this chapter:

                          t ProMAX Geometry Assignment Map
                          t Loading Geometry Directly to Field Data
                          t Description of Manhattan 3D Geometry
                          t Observers Report
                          t 3D Land Geometry Spreadsheet
                          t Final QC Plots From the Database
                          t Load the Geometry to the SEGY Data
                          t Graphical Geometry QC
                          t Geometry Core Path Overview
                          t Details of the Geometry Programs
                          t Pre-Geometry Database Initialization
                          t Inline Geometry Header Load after Pre-Initialization




Landmark                                     ProMAX 3D Seismic Processing and Analysis          2-1
Chapter 2: ProMAX 3D Geometry




ProMAX Geometry Assignment Map

                                     Global Options

                 UKOOA           ASCII
      O.B.                                                                    Field
      Notes                                                                    Data


                UKOOA
                Import                                          SEG-? Input
                     Spreadsheet
                     Import

                                 Database
                                 Import
                                                           Seismic Data
                                                            (ProMAX)
                                             Extract
                                             Database
                                             Files
           Geometry                                            Inline Geom
          Spreadsheet                                          Header Load



                  Ordered Parameter                                              Disk Data
                                                                                 Output
                         Files
                                                                     Disk Data
                                                                     Output

                                     Inline Geom
                                     Header Load
                                                   Valid Trace
                                                   Numbers
                                                   Overwrite
                                                   Trace Headers
          Seismic Data                                                    Seismic Data
              (ProMAX)                                                     (ProMAX)




2-2            ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                            Chapter 2: ProMAX 3D Geometry




      Loading Geometry Directly to Field Data

                           For typical 3D processing, we recommend first building the
                           geometry and then assigning it to the traces when you first read
                           the field tapes. In this way, you avoid reading the data twice:
                           once to count the traces and once to read and load the headers.


                             From Field Notes and Survey
           O.B.    UKOOA      ASCII                                         Field
           Notes                                                            Data

                   UKOOA                                         SEG-? Input
                   ImportSpreadsheet
                         Import
                                 Database
                                 Import                    Seismic Data
                                                            (ProMAX)
               Geometry
               Spreadsheet
                                                       Inline Geom
               Ordered Parameter                       Header Load           Disk Data
                                                                             Output
                     Files




                                                                      Seismic Data
                                                                       (ProMAX)



                           In the following example we will read the data directly from the
                           SEG-Y version of the field tapes and use the header words FFID
                           and Recording Channel number to match each trace with its
                           corresponding information in the database.




Landmark                              ProMAX 3D Seismic Processing and Analysis         2-3
Chapter 2: ProMAX 3D Geometry




Description of Manhattan 3d Geometry




                       Manhattan 3D - Shot and Receiver Basemap


2-4          ProMAX 3D Seismic Processing and Analysis            Landmark
                                                                Chapter 2: ProMAX 3D Geometry




Observer’s Report


               Source Interval=N/A              Receiver              Sample       Record
                    (random)                    Int.=110’            Interval=     Length=
                                              Cable Int.=110’          4 ms        2.0 sec.
            Source                 Field       No. of Chan/          Receiver      Receiver
            Station                 File           Shot               Station       Station
           Numbers                 ID’s                                 at            at
                                                                      Chan 1      Last Chan
       1001 - 1016        1 - 16             240                1                240
       1017 - 1024        17 - 24            240                73               312
       1025 - 1031        25 - 31            240                145              384
       1032 - 1043        32 - 43            240                217              456
       1044 - 1053        44 - 53            240                289              528
       1054 - 1061        54 -61             240                361              600
       1062 - 1070        62 - 70            240                433              672
       1071 - 1075        71 - 75            216                505              720
       1076               76                 120                505              624
       1077 - 1081        77 - 81            216                505              720
       1082               82                 120                505              624
       1083 - 1085        83 - 85            216                505              720


                               Manhattan 3D Observers Reports

                        Group Interval
                                   110 ft. Inline by 110 ft. cable spacing

                        Shot interval
                                   N/A --- Shots are positioned randomly

                        Azimuth
                                   5.6 degrees East of North

                        CDP Spacing
                                   55 ft. inline by 55 ft. crossline




Landmark                                   ProMAX 3D Seismic Processing and Analysis          2-5
Chapter 2: ProMAX 3D Geometry




First Look at the Trace Data

                        1. Add a line to your area called “Database from survey”

                        2. Build the following flow:


                       Editing Flow: 01 - View SEGY Gathers

                       Add           Delete          Execute          View         Exit

                       SEGY Input
                             Type of storage to use: ----------------------------- Disk Image
                             Enter DISK file path name: -----------------------------------------
                                     --------/misc_files/3d/manhattan3d_segy_disk
                             MAX traces per ensemble: ------------------------------------240
                             Remap SEGY header values?: --------------------------------No
                       Trace Display
                             ---- Use All Default Parameters ----

                        3. In SEGY Input, enter your input shot dataset as described by your
                           instructor.

                        4. Use all default parameters for the Trace Display.

                        5. Execute the flow.




2-6          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                      Chapter 2: ProMAX 3D Geometry




3D Land Geometry Spreadsheet

            Any geometry information not taken directly from the trace headers of
            a dataset must be entered via the Geometry Spreadsheet. The
            spreadsheet is a window into the contents of the Ordered Parameter
            Files (OPFs) which comprise the database. If information has been
            written to the OPFs using Extract Database Files, in either full extract or
            pre-init modes, it is immediately available in the spreadsheet.

            The options in the main Geometry Spreadsheet window allow you to
            launch separate spreadsheets for editing receiver and source locations,
            and receiver pattern relationships. In addition to editing individual cell
            entries, each spreadsheets can also import ASCII information.

            The spreadsheets offers options for the interpolation, extrapolation, and
            math manipulations of the spreadsheet entries. The spreadsheet also
            generates graphical displays for geometry QC. Basemap, XYGraph, and
            Point Cloud QC displays can be generated for most attributes in the
            database.

            In this section you will learn the following:

            •   How do use the Receivers spreadsheet to identify each receiver and
                specify their locations and elevations by importing SEG-P1 survey
                data with the ASCII import function.
            •   How to use the Sources spreadsheet to identify each source and
                specify their locations and elevations and specify a receiver pattern
                associated with each source.
            •   How to build receiver patterns using the Patterns spreadsheet.
            •   How to define and QC your CDP binning parameters using the 3D
                Bin tools.
            •   Once the source, receiver, and pattern spreadsheets are completed,
                you must define the CDP bin parameters. There are three ways to
                define the CDP bin grid parameters:
                • Manually compute all of the required information.

                •   Interactively overlay a proposed CDP binning grid.

                •   Automatically compute a CDP bin grid based on an azimuth and
                    bin sizes.

            Of these options, the last two are used most often, unless you have some
            pre-computed information.



Landmark                      ProMAX 3D Seismic Processing and Analysis             2-7
Chapter 2: ProMAX 3D Geometry


       3D Land Geometry Spreadsheet
                        1. Add a line to your area called “database from survey/obs logs”.

                        2. Build the following flow:


                       Editing Flow: 02 - spreadsheet

                       Add            Delete          Execute          View        Exit

                       3D Land Geometry Spreadsheet

                        3. Execute the flow.

                        4. Select Setup from the main pull down menu.




                        The setup menu pictured on the following page allows you to define
                        global information applying to the configuration and operation of the
                        Geometry Spreadsheet.

                        5. Select the Assign Midpoints Method: Matching pattern numbers
                           in the SIN and PAT spreadsheet which is the default.

                             This option allows you to build geometry by on defining patterns of
                             receivers and then declaring which pattern is used with each source.

                        6. Select 110’ for the nominal receiver station interval and crossline
                           separation and do not fill out the source station interval.

                             These numbers are only used for QC purposes.

                        7. Do not fill in the nominal survey azimuth.

                             We will interactively determine these values and will enter them
                             later.




2-8          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                     Chapter 2: ProMAX 3D Geometry


                          Setup Window




           8. Answer No to Base Source station coordinates upon a match
              between source and receiver station numbers.

              In our case the sources are numbered 1001-1085 and the receivers
              are 1-720. There is no relationship.

           9. Enter shot holes for source type.

           10. Set units to Feet.

           11. Do not specify a coordinate origin.

           12. Specify the font assignment if you wish to change the display.

           13. Click on the OK button.

Landmark                     ProMAX 3D Seismic Processing and Analysis          2-9
Chapter 2: ProMAX 3D Geometry


       Receivers Spreadsheet
                        1. Click on Receivers in the main Spreadsheet window to bring up the
                           Receivers spreadsheet.

                        2. Select File ¦ Import from the pull down menus on the
                           spreadsheet to read the contents of an ASCII file into the
                           spreadsheet.

                        When working with ASCII file import there are three required
                        steps:
                            •   Identify the ASCII file

                            •   Define which numbers are in which columns, and

                            •   Define which “cards” or rows to exclude from the import.

                        3. Enter the directory path that contains the desired dataset followed
                           by a /* as directed by your instructor. Double click the file
                           segp1.3d.rec or select the file and then click OK.

                        4. Click Format and enter a name for a format description containing
                           ASCII import column definition information. For Example:
                           “Manhattan receiver format”

                        5. In the Column Import Definition Menu, click on the parameter
                           attribute name, such as station, and define the column information
                           Note that the selection turns white.

                         NOTE:

                         Look at the Mouse Button help descriptions at the bottom of the ASCII text window.
                         Note that they reflect the MB1 “press and drag” operation for column definition



                        6. Highlight the columns that contain the numbers for the attribute
                           you selected while holding down MB1 and moving from left to
                           right in the file import window.

                        7. Repeat the previous two steps for the X and Y coordinates and the
                           elevations.

                        Switch to “card” or row exclusion mode.
                        8. With the cursor positioned over the Parameter Column notice that
                           the MB3 help will toggle the Column Definition Off.



2-10         ProMAX 3D Seismic Processing and Analysis                                           Landmark
                                                            Chapter 2: ProMAX 3D Geometry


            9. Click MB3 with the cursor positioned over the word “Station” or
               one of the other columnar attributes..

           Note:
           MB3 turns
           column
           definition
           off when the
           cursor is in the
           attribute list
           column




              NOTE:

              Look at the Mouse Button help descriptions at the bottom of the ASCII text window.
              Note that they now reflect block selection and deletion options.



            10. Use MB1 and MB2 to define title rows, blank rows, and rows with
                information that you do not want to import, and press Ctrl-d.

                This writes a “Ignore record for import” message on all the defined
                rows.

            11. From the main import menu, select Filter.

                This will check for any “cards” with inappropriate information, and
                allows you to interactively delete them.

            12. From the main import menu, select Apply.



Landmark                         ProMAX 3D Seismic Processing and Analysis                  2-11
Chapter 2: ProMAX 3D Geometry


                        13. Select Overwrite ALL existing values with new import values
                            and click OK.

                        This removes your import menus and the receiver spreadsheet should be
                        filled out with the receiver stations numbers, X and Y coordinates and
                        elevations.




                                  Receivers Spreadsheet

                        14. Make sure you have 720 stations defined in your receiver
                            spreadsheet, no blank lines at the end, and that the information
                            looks correct.

                        15. Use the File ¦ Exit pulldown menu to save the spreadsheet
                            information and exit.




2-12         ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                                   Chapter 2: ProMAX 3D Geometry


      Sources Spread Sheet
                    1. Click on Sources to bring up the Sources Spreadsheet.

                    2. Select File ¦ Import from the pull down menus on the spreadsheet
                       to read the contents of an ASCII file into the spreadsheet.

                    3. Enter the directory path that contains the desired dataset followed
                       by a /* as directed by your instructor. and select the file
                       segp1.3d.sou. Double click the file name or select the file and then
                       click OK.

                    4. Click Format and enter a name for a format description containing
                       ASCII import column definition information. In the “Column
                       Import Definition” menu, click on the parameter attribute name,
                       such as station, and define the column information Note that the
                       selection turns white.

                     NOTE:

                     Look at the Mouse Button help descriptions at the bottom of the ASCII text window.
                     Note that they reflect the MB1 “press and drag” operation for column definition



                    5. Highlight the columns that contain the numbers for the attribute
                       you selected while holding down MB 1 and moving from left to
                       right.

                    6. Repeat the previous two steps for all the attributes you want to
                       import from your ASCII file. Make sure that you import the
                       STATION column and in addition read the X and Y coordinates, the
                       elevations, uphole times and shot depths.

                    Switch to “card” or row exclusion mode.
                    7. With the cursor positioned over the Parameter Column notice that
                       the MB 3 help will toggle the Column Definition Off.




Landmark                                ProMAX 3D Seismic Processing and Analysis                  2-13
Chapter 2: ProMAX 3D Geometry


                        8. Click MB3 with the cursor positioned over the word “Station” or
                           one of the other columnar attributes.



                             Note:
                             MB3 turns
                             column
                             definition
                             off when the
                             cursor is in the
                             Parameter list
                             column




                         NOTE:

                         Look at the Mouse Button help descriptions at the bottom of the ASCII text window.
                         Note that they now reflect block selection and deletion options.



                        9. Use MB1 and MB2 to define title rows, blank rows, and rows with
                           information that you do not want to import, and press Ctrl-d.




2-14         ProMAX 3D Seismic Processing and Analysis                                           Landmark
                                                  Chapter 2: ProMAX 3D Geometry


              This writes a “Ignore record for import” message on all the defined
              rows.

           10. From the main import menu, select Filter.

              This will check for any “cards” with inappropriate information, and
              allows you to interactively delete them.

           11. From the main import menu, select Apply.

           12. Select Overwrite ALL existing values with new import values
               and click OK.

              This removes your import menus and the sources spread sheet
              should be filled out with the receiver X and Y coordinates,
              elevations, shot depths and uphole times.




           13. Make sure 85 shots are defined in your sources spreadsheet, and the
               information looks correct.

           14. Use the File ¦ Save pulldown menu to save the information in the
               sources spreadsheet.

              You are not finished with the shot information yet. We will return to
              the sources spreadsheet after completing the pattern specification.




Landmark                    ProMAX 3D Seismic Processing and Analysis         2-15
Chapter 2: ProMAX 3D Geometry


       Basemap QC and setting the Prospect Level Azimuth
                        1. Open the receivers spreadsheet again by clicking on Receivers in the
                           main spreadsheet menu.

                        2. QC the survey information by selecting View ¦ View All ¦
                           Basemap from the Receivers Spreadsheet.




               Highlight Contributors to
               cross domain ICON
               Also measures Distance
               and Azimuth




                                                 Cross Domain QC

                        3. Using the Cross Domain Icon (“Double Fold Icon”) use the MB3
                           option to measure the azimuth along a cable line.

                            You should find a value somewhere between 5.5 and 6 degrees East
                            of North.

                        4. Reopen the “Setup” window from the main Geometry window.



2-16         ProMAX 3D Seismic Processing and Analysis                               Landmark
                                                   Chapter 2: ProMAX 3D Geometry


              Enter this angle (5.6 degrees) for Nominal Survey Azimuth.

           5. Close the “Setup” window.

           6. Overlay a color contour graph of the source and receiver elevation
              on the top of the Basemap.

              To create this plot, click on Display ¦ Recs&Sources ¦ Color
              Contour ¦ Elevation. This overlays a colored elevation contour on
              top of the basemap.

           7. Select the Views ¦ Remove ¦ Shot and Receiver based Field of
              Elevation option at the top of the color contour display to remove
              the shot and receiver elevation display.

              You can remove attributes or place different attributes to the top,
              using options under the Views menu.

           8. Open the Sources spreadsheet

           9. Click on the Report icon on the XYGraph Display.

              Click MB1 on any shot location on the basemap. This takes you to
              that shot location in the source spreadsheet.

              Since you generated the basemap from the Receivers spreadsheet,
              the shots are overlaid and “dominant”. Therefore, the Sources
              spreadsheet must be open.


            Note:

            If you generated the basemap from the sources spreadsheet, then the
            receivers are overlaid and “dominant” and the map is expecting to talk
            to the Receiver spreadsheet. This spreadsheet must be open for the
            report to respond to the spreadsheet.


              You can control which map is overlaid using the Views ¦
              Transparent pulldown menus.

              Select the map that you want to be “on top” of the others by clicking
              MB1 on the map name.

           10. Exit the XYGraph and the Receiver spreadsheet using the File ¦
               Exit ¦ Confirm and File ¦ Exit pull down menus.


Landmark                    ProMAX 3D Seismic Processing and Analysis          2-17
Chapter 2: ProMAX 3D Geometry


       Patterns Spreadsheet
                        1. From the main Geometry menu, select Patterns to fill out receiver
                           pattern information. Two windows will appear.




                        2. In the small window enter 240 for the maximum number of
                           channels per shot, and select Varying number of channels/record.

                        3. Fill out the Pattern Spreadsheet specifying one pattern varying from
                           channel 1 to channel 240 by one and from receivers 1 to 240 by
                           one. Leave the Receiver Line number blank in this case.




                            Multiple patterns would be required if the gap changes in size or
                            location, relative to the channel numbers.

                            Multiple patterns would also be required in the case where multiple
                            cable lines are used and the receiver line numbers change for
                            different groups of shots.

                        4. Click on File ¦ Exit from the Patterns Spreadsheet.

                            If the pattern was mistyped, the error column will have stars in it and
                            the pattern spreadsheet will not exit. Highlight the error column and
                            look at the information at the bottom of the spreadsheet for a
                            description of the problem. Fix the problem, and attempt to exit
                            again.




2-18         ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                             Chapter 2: ProMAX 3D Geometry


      Complete the Sources Spreadsheet
                    1. Fill out the FFID, Pattern, Pat Num Chn, and Pat Shift columns.

                       •   The FFID’s start at 1 and increment by 1 for a total of 85 FFIDs.

                       •   All of the shots use the same pattern which defines continuously
                           numbered receivers; therefore, we can fill the Pattern column
                           with 1’s.

                       •   Num Chn is the number of channels per pattern. Use the
                           observer’s log to get the number of channels per shot.

                       •   Pat Shift is the shift, in the receiver station number of the first
                           channel relative to that entered in the Patterns Spreadsheet. Use
                           the observer’s log to calculate these values. These will not be the
                           first receiver station numbers, but will be the receiver number -1.

                       •   Do not fill in the Shot Fold* column. These values will be
                           automatically calculated when you assign midpoints.




                    2. In the source spreadsheet main menu, select File ¦ Exit to save
                       and exit the Sources spreadsheet.




Landmark                             ProMAX 3D Seismic Processing and Analysis           2-19
Chapter 2: ProMAX 3D Geometry


       CDP Binning
                        This exercise illustrates the CDP binning procedures.

                        1. In the main Geometry menu, click on Bin.

                            A submenu appears with options for Assigning the traces to
                            midpoints, defining the bin grid, binning the data, quality controlling
                            the binning, and finalizing the database.




                        2. Select Assign midpoints by: Matching pattern number in the
                           SIN and PAT spreadsheets, and click on Ok.

                            In this case the Assignment step is performing the following
                            calculations:

                            •   Computes the SRF number for each Trace in the TRC database.

                            •   Computes the Shot to Receiver Offset (Distance).

                            •   Computes the Midpoint coordinate between the shot and
                                receiver.

                            •   Computes the Shot to Receiver Azimuth.




2-20         ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                             Chapter 2: ProMAX 3D Geometry


                    3. An Assignment Warning window will pop up warning that some or
                       all of the data in the Trace spreadsheet will be overwritten. Click on
                       Proceed.




                    4. A number of progress windows will flash on the screen as this step
                       runs. A final Status window should notify that you successfully
                       completed geometry assignment. Click on OK.

                       If this step fails, you have an error in your spreadsheets somewhere.
                       Not much help is given to you, but the problems are usually related
                       to the pattern definitions and spread layout as defined in the Sources
                       Spreadsheet.

                    5. Reopen the Sources spreadsheet and check to make sure your Num
                       Chn column values and the Shot Fold* column values match.

                       If these columns do not match, check the Pat Shift values and rerun
                       Assign midpoints in the Bin window.


      Interactive Spread QC using XYgraph
                    A useful QC to perform at this point is to redisplay a Basemap and use
                    the Cross Domain Icon to view the receivers that have been defined as
                    live for each shot.

                    1. Open the Receivers spreadsheet again by clicking Receivers in the
                       main Geometry menu.

                    2. Generate a Basemap by selecting View ¦ View All ¦ Basemap
                       from the Receiver spreadsheet pull down menus.




Landmark                              ProMAX 3D Seismic Processing and Analysis          2-21
Chapter 2: ProMAX 3D Geometry


                                        Interactive Spread QC using XYgraph




              Cross Domain Icon
              highlights contributors




                         3. Using the Cross Domain Icon (“Double Fold Icon”) use the Mouse
                            Button 1 and 2 options to see which receivers have been defined to
                            be live for each shot and which shots contribute to each receiver.

                            Press and hold down MB1 on a shot location and continue to hold
                            the button as you move from one shot the another.




2-22         ProMAX 3D Seismic Processing and Analysis                               Landmark
                                                             Chapter 2: ProMAX 3D Geometry


      Defining the CDP binning grid
                     There are three ways to define the CDP bin grid parameters:

                         •   Manually compute all of the required information

                         •   Interactively define a proposed CDP binning grid, or

                         •   Automatically compute a CDP bin grid based on an azimuth and
                             bin sizes.


      Interactive Grid Definition
                     For this example we will look at the second option and interactively
                     define a grid of CDP bins.

                     1. Select Define binning grid from the 3D Binning and QC window
                        and click on Ok.




                         This will bring up a small map window.

                     2. Select Display ¦ Midpoint ¦ Control Points ¦ Black
                        (depending on the color of the background).




Landmark                              ProMAX 3D Seismic Processing and Analysis        2-23
Chapter 2: ProMAX 3D Geometry


                        You should get the following plot:




                         Mid-point Scattergram for CDP Binning


2-24         ProMAX 3D Seismic Processing and Analysis           Landmark
                                                           Chapter 2: ProMAX 3D Geometry


                 3. Click on Grid ¦ Display.

                     This step overlays a bin grid on your subsurface data. The default is
                     a 10 cell by 10 cell grid which is 100’ by 100’ and oriented at an
                     azimuth of 0o.

                 4. Click on Grid ¦ Parameterize, and change the cell size along and
                    across Azimuth to 55’ by 55’. You may also enter an azimuth of 6o,
                    determined from the receivers. Then click on the Green Traffic light
                    icon.

                     This interactively alters the bin grid size. You can completely define
                     your bin grid with the Parameterize menu.

                     Now we can use the icons on the side of the window to orient the grid
                     to best fit the subsurface data. First, read the following short
                     description of each of the icons.


           A description of the interactive binning functionality
                 When an existing grid has been opened or a default grid is displayed,
                 you have the capability of entering grid parameters, such as bin size, bin
                 rotation angle, and number of bins. The icons on the side of the window
                 allow you to interactively control these items. Below is a description of
                 the function of each of the icons:

                 •   Zoom: This icon will put the display area in zoom mode. Clicking,
                     and holding down MB1 within the display area will define one
                     corner for the zoom rectangle. Move the cursor to an opposing
                     corner (note the rubber banding rectangle as the cursor moves) and
                     release MB1 to complete the rectangle definition. Clicking MB1
                     once will cancel the current zoom.

                 •   Rotate: This icon rotates the binning grid about a selected point. To
                     select the point of rotation, move the cursor to the desired location
                     for the point within the display area and click MB2. The point of
                     rotation is displayed as a large crosshair. To rotate the binning grid,
                     click and hold MB1 within the display area and move the cursor.
                     The grid will rotate with cursor movement. Release MB1 when the
                     desired orientation has been reached. Click MB3 within the display
                     area to remove the point of rotation.

                 •   Move: This icon translates or moves the grid. To move the grid,
                     click and hold MB1 within the display area. Move the cursor until
                     the grid is in the desired location and then release MB1.


Landmark                           ProMAX 3D Seismic Processing and Analysis           2-25
Chapter 2: ProMAX 3D Geometry


                        •     Size Grid Cells: This icon adjusts the grid cell dimensions by either
                              expanding or contracting the cells along one axis or the other. MB1
                              and MB3 will expand or contract the cells respectively. Press and
                              hold either button near an edge of a cell on the outside of the grid,
                              and then move the cursor. The cells will change size with the mouse
                              movement. Release the button when the desired size has been
                              reached. Click and hold MB2 to grab the nearest edge and move it
                              and the cells will adjust size to meet the new location of the edge.
                              Release MB2 when the desired size has been found.

                        •     Add/Delete Grid Cells: This icon adds or deletes rows or columns
                              of cells from the grid. MB1 and MB3 will add or delete cells. Click
                              either button near an outside edge of the grid and a group of cells
                              will be added or deleted. Press and hold MB2 to set the edge of the
                              grid to the location of the cursor. Release the button when the
                              number of cells is as desired.

                        •     Spider: This icon displays selected bins in one of two spider plot
                              formats. Move the cursor to the desired bin for the spider plot and
                              click either MB1 or MB3. MB1 generates a spider plot consisting
                              of line segments drawn from the bin center to the midpoint
                              locations within the bin. MB3 generates a source receiver spider
                              plot displaying the delta x and y values for the source receiver pairs.
                              Multiple bins may be selected with spider plots being generated for
                              each. The spider plot will be updated to reflect any changes in bin
                              size and orientation when the grid position or rotation is modified.

                            Note:

                            The performance of these operations is dependent upon the number
                            of spider plots currently active.


                 Continue with the interactive bin definition
                        5. Click the Add/Delete Grid Cells icon and follow the mouse helps
                           to add bins to the edges of your survey.


                        6. Use the Rotate icon to rotate your grid to match the azimuth of the
                           survey.

                              A value of 5.6o is appropriate.

                        7. Use the Move icon to move your grid to align the lower left hand
                           corner of the survey.


2-26         ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                    Chapter 2: ProMAX 3D Geometry


              Check any subsurface areas with questionable binning by using the
              Zoom icon.

              At this point, the midpoints should be in the center of the bins.

           8. Select Grid ¦ Drawing to check how well the midpoints are
              centered in your grid. To adjust the grid, use the Move icon.

              This will draw an axis through the center of the grids as opposed to
              drawing the grid/bin edges. The midpoint clusters appear at the grid
              cross points (which are the bin centers).

           9. Click on Grid ¦ Drawing again to return to your original grid
              boxes.

           10. Check CDP smear by using the Spider Plot icon.

              This shows where your individual midpoints are in relationship to
              the bin center. As you move the grid, the spider plot changes to the
              selected bin. Ideally, you would want to minimize the scatter within
              the bin.

           11. Reuse any of the icons to optimally overlay the bin grid on the
               subsurface data.

           12. Check the size of your grid by clicking on Grid ¦ Parameterize.

              In order to be consistent with later instructions, please make sure
              you have a grid that is 42 by 79 (nx by ny) at an azimuth of 5.6
              degrees.

           13. Click on Grid ¦ Save when you are satisfied with your grid.

              You are prompted to enter a name for your grid. A suggestion would
              be to name this grid “ CDP Grid - 55x55 ft - 5.6 degrees - origin in
              SW corner)

            Note:

            If you do not save your grid before leaving this plot, you will loose
            your work.


           14. Exit from the XYGraph using File ¦ Exit ¦ Confirm and return
               to the 3D Binning and QC submenu.



Landmark                    ProMAX 3D Seismic Processing and Analysis             2-27
Chapter 2: ProMAX 3D Geometry


       CDP Bin Application
                        15. Select Bin midpoints and click Ok. The following window with
                            default parameters will appear:




                                                    16              18
                                             17
                                                         19
                                                               20




                        16. Click Load, and select the bin grid that you just saved. The
                            parameters describing your grid will be loaded into each box.

                        17. Select Inlines parallel to grid Y axis, which is parallel to the
                            defined azimuth.

                            In our case, this is parallel to the cables.

                        18. Change the offset binning parameters to be 0- 5000 with and
                            increment of 220. The selection of 220 ft per offset bin is relatively
                            arbitrary here. Normally the offset binning will be some multiple of
                            the group interval.

                        19. Save the grid definition by clicking on Save.

                        20. Click on the “Apply” button the binning definition to assign each
                            trace to a single CDP as defined by the bin definition.


2-28         ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                              Chapter 2: ProMAX 3D Geometry


                      21. Several status windows will appear on your screen. Click Ok in the
                          final window.

                      22. Click on Cancel to exit the binning window.

      QC Binning with Fold Plot
                      23. Select QC Bin data..




               24



               24

                 25


                      24. Click the QC Bin Space button and select your bin grid from the
                          list.

                      25. Click Ok to bring up the Coordinate Space Fold display:

                         This option displays a map of subsurface coverage versus x,y. The
                         maximum fold value should be 16.

                      26. Select Finalize Database, and click Ok.




                      27. After the finalization is complete, select Cancel to close 3D
                          Binning and QC window.



Landmark                               ProMAX 3D Seismic Processing and Analysis         2-29
Chapter 2: ProMAX 3D Geometry


                        28. Select File ¦ Exit from the main spreadsheet menu to exit the
                            Geometry Spreadsheet.

                        You now have a fully populated database ready to be loaded to the trace
                        headers.




2-30         ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                      Chapter 2: ProMAX 3D Geometry




Final QC Plots from the Database

             Listed below are some useful QC plots that you can generate from the
             database using DBTools and XDB.


             DBTools; View ¦ Predefined ¦ CDP fold map
             •   used to check CDP fold for variations


             DBTools; View ¦ Predefined ¦ Receiver fold map
             •   used to check for variations in receiver multiplicity


             DBTools; View ¦ Predefined ¦ Source fold map
             •   used to check for variations in number of channels per source


             XDB; Wire/Field; SRF: X,Y, ELEV
             •   used to check receiver elevations


             XDB; Wire/Field; SIN: X,Y, ELEV
             •   used to check shot elevations


             DBTools; View ¦ Predefined ¦ SIN-SRF-Offset
             •   used to check the live receivers for each shot


             DBTools; View ¦ Predefined ¦ ILN-XLN-CDP
             •   used to map 3D CDP numbers to inline and crossline coordinates


             DBTools; View ¦ Predefined ¦ Offset-CDP-SIN
             •   used to check offset distribution in CDPs for velocity analysis
                 placement and DMO binning




Landmark                       ProMAX 3D Seismic Processing and Analysis           2-31
Chapter 2: ProMAX 3D Geometry


                        2D plots of SIN vs. UPHOLE, DEPTH, NCHANS and SRF vs.
                        FOLD
                        •   used to check various attributes for sources and receivers


                        2D plots of ILN and XLN vs. FOLD
                        •   used to find minimum and maximum live inline and crossline
                            numbers after binning




2-32         ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                     Chapter 2: ProMAX 3D Geometry




Load the Geometry to the SEGY Data

            The final step of the geometry installation procedure is to load the
            information from the database into standard ProMAX trace headers
            using the Inline Geometry Header Load process.

            Inline Geom Header Load is run in a flow between a data input step and
            a data output step. If desired, additional trace processing tools can be
            included in the flow.

            This process may also be used with output in overwrite mode if a pre-
            existing dataset is available that is already stamped with “valid trace
            numbers”.

            There are two modes of operation for Inline Geom Header Load. One
            mode assumes that there is a direct mapping of a trace in a data file to a
            trace in the database by the “valid trace number”. This will be the case
            if you ran the Extract Database Files process in either mode and you
            wrote a new file. If you are reading data directly from field tapes, then
            they are not stamped with the “valid trace number” and a different mode
            of identifying traces must be used.

            In the sequence where you read directly from field tapes, you have to
            identify traces based on available header words. Combinations of
            available header words are endless depending on a lot of factors,
            including:

            •   when the data were recorded

            •   what format the data were recorded

            •   what recording system was used.

            In general, for 3D processing, we recommend to first build the geometry
            database and then assign its contents to the traces on the first read from
            field tapes. In this way, you only have to read the data twice: once to
            count the traces and once to read the headers.




Landmark                      ProMAX 3D Seismic Processing and Analysis          2-33
Chapter 2: ProMAX 3D Geometry


                        1. Copy your flow “01 - View SEGY gathers”, and edit it to look like
                           the following:

                       Editing Flow: 03 - load geom to headers

                       Add            Delete          Execute          View         Exit

                       SEGY Input
                             ----Use the same parameters as before----
                       Inline Geom Header Load
                             Primary header to match database-----------------FFID
                             Secondary header to match database ------------None
                             Match by valid trace number?------------------------No
                             Drop traces with NULL CDP headers?----------------No
                             Drop traces with NULL receiver headers?-----------No
                             Verbose Diagnostics?-----------------------------------No
                       Disk Data Output
                             Output Dataset Filename----------------shots - raw data
                             New, or Existing, File?-------------------------------New
                             Record length to output--------------------------------0.
                             Trace sample format-------------------------------16 bit
                             Skip primary disk Storage?----------------------------No

                        2. In SEGY Input, enter your input shot dataset as described by your
                           instructor.

                        3. In Inline Geom Header Load, match a primary header of FFID to
                           the database with no secondary header.

                             Recording channel number is assumed and there are not any “valid
                             trace numbers”, so we cannot match by “valid trace numbers”. You
                             have binned all traces; therefore, do not drop any traces. Unless you
                             have a problem, there is no need for verbose diagnostics.

                        4. In Disk Data Output, enter a new output dataset filename.

                        5. Execute the flow.




2-34         ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                               Chapter 2: ProMAX 3D Geometry




Graphical Geometry QC

                    After loading the geometry from the database to the trace headers, you
                    can use the Graphical Geometry QC process to look at the shot records
                    with linear moveout applied at the assigned offsets. The traces will line
                    up vertically as a function of their assigned surface receiver position.

                    On this display you will want to check all of the shots, making sure first
                    arrivals appear at approximately the same time. You can also determine
                    if traces were assigned to the correct receivers by following traces
                    vertically. If reversed polarity receivers exist, then all traces recorded at
                    that receiver will be reversed and should align themselves on the same
                    trace.


      Graphical Geometry QC Flow
                    1. Build the following flow:

                   Editing Flow: 04 - Graphical Geom QC

                   Add            Delete           Execute           View         Exit

                   Graphical Geometry QC*
                         Select input trace data file-------------”raw shot data”
                         Sin and SOU_SLOC range of dataset-----------------*:*
                         dB/sec gain value to apply-----------------------------6.
                         Specify LMO velocity functions(s)--------------1:0:9000
                         Additional bulk shift------------------------------------25
                         Maximum time for each spliced trace---------------100
                         Maximum number of shots to splice-------------------10
                         Resulting max number of traces/ screen ----------- 340
                         Select display device-------------------------This Screen
                         Scalar for sample value multiplication ---------------1.
                         Trace scaling option -----------------------Entire Screen




Landmark                               ProMAX 3D Seismic Processing and Analysis            2-35
Chapter 2: ProMAX 3D Geometry




Geometry Core Path Overview

       How to Decide on the Primary Geometry Path
                                          Vector Diagram
             OPTIONS                                             QUESTIONS

       * Pre-Initialization
                                          no        * Does Shot and Receiver X, Y, and
                                                      station information exist in the
                                    yes               headers and do you want to use it?
                                               no
       * Full Extraction
                                             no
                                                    * Do you want to minimize the
                                                      number of times that you have to
                                           yes        read the data?
       * From Field Notes and Survey
                    no
                      yes                               * Do I have “Valid Trace Numbers”?


                                          Table Diagram

                        Question                           Answer        Option

                        Is shot and receiver station,      Yes           Full Extraction
                        and x,y information in the
                        headers; do you want to use
                        it?                                No            Ask the next question

                        Do you want to minimize the        Yes           From Field Notes and Survey
                        number of times to read the
                        data?
                                                           No            Partial Extraction




2-36         ProMAX 3D Seismic Processing and Analysis                                        Landmark
                                                               Chapter 2: ProMAX 3D Geometry


      Transferring the Database to Trace Headers
                     When the database is completed, the information contained in it is
                     transferred to trace headers. The following question determines how to
                     match a trace in the data file to a trace in the database:

                      Question                        Answer       Option

                      Was a Full or Partial           No           Inline Geom Header Load by
                      Extraction used to create the                Chan and other trace header
                      database and a new output file                words.
                      written?

                                                                   Inline Geom Header Load by
                                                      Yes          valid trace number




Landmark                                 ProMAX 3D Seismic Processing and Analysis         2-37
Chapter 2: ProMAX 3D Geometry




Details of the Geometry Programs

                        In this section we will look in detail at the functions performed by the
                        main programs used in the geometry assignment process. The specific
                        processes that will be addressed are:

                        •   Inline Geom Header Load

                        •   Extract Database Files

                        •   Geometry Header Preparation

                        Inline Geom Header Load is the main program used to assign geometry
                        values to individual trace headers from the OPF database files. One of
                        the main issues related to this geometry assignment procedure is to
                        define how a trace in a data file will be identified in the Trace Ordered
                        Parameter file. One of the options is to use a specific trace header word
                        called the “valid trace number”. In order to utilize the “valid trace
                        number” we will have to spend some time discussing it’s origin and how
                        it can be used.

                        Another program that may be used in the geometry assignment
                        procedure is called Extract Database Files. We will see that this program
                        is one of the ways that the “valid trace number” can be generated by
                        running it in either the Partial or Full extraction modes.

                        Geometry Header Preparation is another program that may be selected
                        in the geometry assignment procedures. This program can be used for a
                        variety of different purposes. We will look specifically at how it can be
                        used when dealing with the problem of duplicate Field File
                        Identification Numbers.


       Steps Performed by Inline Geom Header Load
                        •   Inline Geom Header Load is the program that populates the trace
                            headers of an input data file with the geometry information stored
                            in the database.

                        •   The outcome from running this program is to have a database and a
                            data file that “match”.




2-38         ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                              Chapter 2: ProMAX 3D Geometry


                    •   This means that every trace in the output data file exists in the
                        database and there is a one to one correspondence in all values in
                        the trace header to those in the database.

                    •   After a successful run each trace will also be assigned the “valid
                        trace number” if it was not pre-assigned using Extract Database
                        Files.

                    There are two major options in this program pertaining to how to
                    identify a trace in the input data file with a trace in the database. These
                    options are:

                    1. to read the “valid trace number” from the input trace header, or

                    2. to read the recording channel number (automatic) and 1 or 2 trace
                       header words that can uniquely identify this trace as having
                       originated from a unique shot (SIN) that exists in the shot database.

                    Once a trace in a data file has been identified in the Trace OPF, the
                    information in all of the OPF’s for that trace is copied to the trace
                    header.


      Valid Trace Numbers
                    Before we proceed, let’s make sure that we understand the idea of the
                    “valid trace number”.

                    •   Understanding this will help us decide on the “best” course of
                        action for our data.

                    •   The “valid trace number” is simply a ProMAX trace header word.
                        Every trace in the database is numbered from 1 to N, where N is the
                        total number of individual traces in the database.

                    •   This is a unique number for each trace in the line or 3D project.

                    •   A “valid trace number” combined with matching geometry is a flag
                        that will allow fast random access sorting of disk datasets.

                    •   Every trace in the TRC database is assigned to a single SIN (shot),
                        SRF (receiver) and CDP. Every trace has an individual Shot to
                        Receiver Offset distance, an individual midpoint X and Y location
                        and many other values that are single numbers, that may, or may not
                        be different for every trace.




Landmark                              ProMAX 3D Seismic Processing and Analysis            2-39
Chapter 2: ProMAX 3D Geometry


                        •   Inline Geom Header Load matches the current trace being
                            processed to the database and then copies all of the trace dependent
                            values as well as the other order values to the trace header. The last
                            thing that happens is that the traces are “stamped” as matching the
                            database.


       Valid Trace Number Origin
                        Where does the “valid trace number” trace header word come from?
                        Luckily, the answer to this is very simple.

                        •   The Extract Database Files program writes this trace header word
                            after it reads and counts a trace that it is entering into the TRC
                            database. In this case the “valid trace number” is pre-assigned.

                        •   If it is not pre-assigned, the Inline Geom Header Load process will
                            create it after it determines which trace in the database corresponds
                            to a trace in a data file.

                        The “valid trace number” is a unique number for every trace and is
                        stored in the trace header as TRACE_NO.

                        This trace header word continues to exist ONLY if you write a new trace
                        file after the extraction procedure.

                        A common question that arises concerns the decision to pre-assign the
                        “valid trace number” using Extract Database Files or to rely on the
                        alternate header identification on the first read of the input data. You
                        may consider using Extract Database Files if there is sufficient
                        information in the trace headers that can be transferred to the database
                        which will save time and increase accuracy of the geometry definition
                        process. The extraction may be run in either the partial extraction or full
                        extraction modes depending on what information is available in the
                        trace headers of the input data.


       Steps Performed By Extraction
                        The steps performed by the extraction options are:

                        Pre-Geometry Initialization (or partial extraction) which is sometimes
                        used when no receiver information exists in the incoming headers.

                        Partial Extraction counts each of the following:

                            •   the number of traces encountered


2-40         ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                              Chapter 2: ProMAX 3D Geometry


                       • the number of shots encountered
                       • the number of traces per shot
                       and then

                       •   writes the trace count number and SIN to the trace header

                    Full Extraction is used when you want to extract the shot and receiver
                    location and coordinate information from the incoming headers.

                    Full Extraction counts each of the following:

                       • the number of traces encountered
                       • the number of shots encountered
                       • the number of traces per shot
                       • the number of receivers encountered
                       • the number of traces per receiver
                       and then

                       •   writes the trace count number and SIN to the trace header

                    IF you have run the extraction in either mode, AND written a new trace
                    data file, AND have not altered the number of traces in the database, you
                    now have “valid trace numbers” in the headers of the output data set
                    which you can use to map a trace in a data file to a trace in the database.

                    This mapping will be performed by Inline Geom Header Load after the
                    database is completed.


      Between Extraction and Geom Load
                    After running Extract Database Files in either mode there are many
                    steps that need to be completed prior to running the inline Geom Header
                    Load.

                    The extraction only partially populates the database. More work will
                    generally need to be done in the Spreadsheets to input the remaining
                    information.

                    After the Spreadsheets are complete, the next step would be to complete
                    the CDP binning procedures and then finalize the database.

                    With the database complete, you can continue with the next step of
                    loading the geometry information from the databases to the trace
                    headers. You may elect to address a trace by it’s “valid trace number”




Landmark                              ProMAX 3D Seismic Processing and Analysis           2-41
Chapter 2: ProMAX 3D Geometry


                        assigned during the extraction or you may read a combination of trace
                        headers to identify the trace.


       Geometry Load Procedures
                        For the first option, Inline Geom Header Load operates as follows:

                        1) Identifies the TRACE_NO of the incoming trace and finds that trace
                        in the TRC database.

                        2) Copies the appropriate TRC order values to the trace header and then

                        3) Finds the shot, receiver, cdp, inline, crossline, and offset bin for that
                        trace. The appropriate values from those orders are then copied to the
                        trace headers as well.

                        In the second option, Inline Geom Header Load does not know exactly
                        which TRACE_NO it is looking for. It does know which channel and
                        shot to look for based on the header word(s) that you selected. Given
                        that this mapping is unique, the program now knows which SIN and
                        CHAN to look for in the TRC database. Once the entry is found, the
                        TRACE_NO is copied to the headers and the steps outlined in the first
                        option are performed.

                        Again, the key to the second option is that you need to identify which
                        shot a trace came from by a “unique” combination of header words for
                        that shot.




2-42         ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                                   Chapter 2: ProMAX 3D Geometry




Pre-Geometry Database Initialization

                          To create a minimum set of entries in the SIN and TRC Ordered
                          Parameter files, based upon the information found in the trace headers
                          of the data passed through the flow, selecting Yes to the option for Pre-
                          Geometry Extraction. Basically this process counts how many traces,
                          different FFIDs, and recording channels were present for each input
                          FFID. Therefore, it can build the TRC and SIN ordered database files.
                          An SRF OPF could be created, and may or may not have any
                          information in it.

                          Note: In general, this process is not recommended for medium to large
                          volume 3D projects.

                                Partial Extraction Flow Chart

                                  Pre-Initialization Path
      O.B.        UKOOA         ASCII                                            Field
      Notes                                                                      Data

                  UKOOA                                               SEG-? Input
                  Import Spreadsheet
                         Import
                                   Database
                                   Import                       Seismic Data
                                                   Extract       (ProMAX)
                                                   Database
              Geometry                             Files
              Spreadsheet
                                                      Builds TRC and SIN
              Ordered Parameter                       OPF’s only                   Disk Data
                                                      Pre Geom Init = yes          Output
                     Files

      Marine Data                   Inline Geom
      SSD correction                Header Load      Valid Trace
                                                     Numbers
                                                     Overwrite             Seismic Data
           Seismic Data                              Trace Headers
                                                                            (ProMAX)
            (ProMAX)




Landmark                                    ProMAX 3D Seismic Processing and Analysis         2-43
Chapter 2: ProMAX 3D Geometry


                        This option may be appropriate for relatively small datasets which only
                        have FFID and CHAN in the input trace headers. This option should be
                        used when reading the field data and writing the data to disk for the first
                        time. In so doing, information, such as FFID, number of shots, number
                        of channels are written to the database, and are then available when the
                        geometry is completed. Selecting this option will also stamp the output
                        dataset with “valid trace numbers”, which allows you to process with
                        trace headers only and overwrite the dataset with updated geometry
                        from the database files. This is an important concept for the Inline Geom
                        Header Load process.

                        In the following example, you will assume that only the FFID and
                        recording channel number exist in the incoming trace headers. This
                        information will be extracted, using the perform pre-geometry database
                        initialization option in Extract Database Files.




2-44         ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                               Chapter 2: ProMAX 3D Geometry


      Pre Geometry Initialization flow
                     1. Make a new line called “from pre-initialization”.

                     2. Build the following flow:


                    Editing Flow: 01 - Pre-geom initialization

                    Add            Delete         Execute          View        Exit

                    SEGY Input
                          Type of storage ------------------------------- Disk Image
                          Enter DISK file path name ---------------------------
                          ----------------/misc_files/3d/manhattan3d_segy_disk
                          MAXIMUM traces per ensemble ------------------- 240
                          Remap SEGY header values ------------------------ NO
                    Extract Database Files
                          Is this a 3D survey------------------------------------ Yes
                          Data Type--------------------------------------------LAND
                          Source index method--------------------------------FFID
                          Receiver index method-----------------------STATIONS
                          Mode of operation --------------------------OVERWRITE
                          Pre-geometry extraction?-----------------------------Yes
                    Disk Data Output
                          Output Dataset Filename---------------”raw shot data”
                          New, or Existing, File?-------------------------------New
                          Record length to output--------------------------------0.
                          Trace sample format-------------------------------16 bit
                          Skip primary disk Storage?----------------------------No

                     3. Enter the parameters for the SEGY-Input process:

                          Enter the full path name to the SEGY input dataset as described by
                          the instructor.

                          There are 240 traces per ensemble.

                     4. In Extract Database Files, select to identify which traces belong to
                        which shots and receivers as follows:

                          Sources: identify by FFID


Landmark                               ProMAX 3D Seismic Processing and Analysis        2-45
Chapter 2: ProMAX 3D Geometry


                            Receivers: identify by STATIONS

                        5. In Extract Database Files, select Yes for the option Pre-geometry
                           extraction.

                            This initializes the SIN and TRC domains of the Ordered Parameter
                            Files, stamps the dataset with valid trace numbers, and allows for the
                            use of overwrite mode when performing the Inline Geom Header
                            Load step later.

                        6. In Disk Data Output, enter the name for a new output file, such as
                           “raw shot data”.

                        7. Execute the flow.

                        After the flow completes:

                        8. Exit the flow building level and select Database from the global
                           command line.

                        9. Check the OPFs, verifying the number of records in the dataset, the
                           number of channels/record, and the FFID range.

                            The only OPF files that should exist are LIN, SIN, and TRC. If SRF
                            exists, this means that you identified traces for receivers by
                            coordinates. You will also find that the SRF OPF has 1 value in it.


       Complete the Spreadsheet
                        In this sequence, the next steps would be to complete the Sources,
                        Receivers and Patterns Spreadsheets and perform the CDP binning
                        similarly to the sequence used in the previous exercise.




2-46         ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                               Chapter 2: ProMAX 3D Geometry




Inline Geom Header Load after Pre-Initialization

                    In this sequence, we ran the Extract Database Files process in the pre-
                    initialization mode. Here, we will read the output data from the pre-
                    initialization step and identify a trace relative to its “valid trace number”
                    with respect to the database.


      Load Geometry to Trace Headers
                    1. If the geometry in the database looks good, build the following flow:

                   Editing Flow: 03 - load geom to headers and QC

                   Add            Delete           Execute           View         Exit

                   Disk Data Input
                         Read data from other lines/surveys --------No
                         Select Dataset------------------”raw shot data”
                         Trace read option------------------------Get All
                         Read the data multiple times?--------------No
                         Process trace headers only?-----------------Yes
                         Override input data’s sample interval -----No
                   Inline Geom Header Load
                         Match by valid trace number?--------------Yes
                         Drop traces with NULL CDP headers?-------No
                         Drop traces with NULL receiver headers?--No
                         Verbose Diagnostics?--------------------------No
                   Disk Data Output
                         Output Dataset Filename------”raw shot data”
                         New, or Existing, File?----------------Overwrite
                         Record length to output------------------------0.
                         Trace sample format-----------------------16 bit
                         Skip primary disk Storage?-------------------No

                    2. In Disk Data Input, enter your input shot dataset.

                         In this sequence, we only process the trace headers.



Landmark                               ProMAX 3D Seismic Processing and Analysis            2-47
Chapter 2: ProMAX 3D Geometry


                        3. In Inline Geom Header Load, match the traces by their “valid trace
                           numbers”.

                            Since the traces were read and counted with Extract Database Files,
                            you have a “valid trace number” to identify a trace. You have binned
                            all traces; therefore, do not drop any traces. Unless you have a
                            problem, there is no need for verbose diagnostics.

                        4. In Disk Data Output, output to the same dataset as specified in Disk
                           Data Input.

                            We will use the overwrite option in conjunction with trace header
                            only processing in the Disk Data Input.

                        5. Execute this flow.

                        In the Extract Database Files path, the Inline Geom Header Load
                        process operates on a sequential trace basis, and includes a check to
                        verify that the current FFID and channel information described in the
                        OPFs matches the FFID and channel information found on each trace of
                        each ensemble. The Inline Geom Header Load process will fail if these
                        numbers do not correspond. You must then correct the situation by
                        changing the geometry found in the OPFs, or possibly by changing the
                        input dataset attributes.




2-48         ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                                           Chapter 3
                               Database from Geometry
                                            Extraction
In many instances you may receive data from contractors or other sources with much of the basic
geometry information already in the trace headers. You may elect to build the database from this
existing information. In the case where you receive the data in pieces (not all at one time) you
may be required to append information to an existing database as more data becomes available.




Topics covered in this chapter:

                          t Overview of Geometry Extraction
                          t Read and Extract the first SEGY file
                          t Complete the Database for the First Half
                          t Load the Geometry to the Trace Headers
                          t Read and Extract the Second SEGY file
                          t Complete the Database for the Second Half
                          t Load the Geometry to the Trace Headers
                          t Exercise Summary
                          t Full Extraction
                          t Processing without a Database




Landmark                                    ProMAX 3D Seismic Processing and Analysis         3-1
Chapter 3: Database from Geometry Extraction




Geometry Extraction
                           For reprocessing, extraction can read information for building the
                           database from the input trace headers. If only part of the information is
                           available, the database completion is performed subsequently within the
                           spreadsheets. If all necessary information is available, the database can
                           be completed in the extraction step without having to work with the
                           spreadsheet or binning tools.

                                    Geometry Extraction
       O.B.        UKOOA         ASCII                                             Field
       Notes                                                                       Data

                   UKOOA                                               SEG-? Input
                   Import Spreadsheet
                          Import
                                    Database
                                    Import                       Seismic Data
                                                    Extract       (ProMAX)
                                                    Database
               Geometry                             Files
               Spreadsheet
               Ordered Parameter                                                    Disk Data
                                                                                    Output
                      Files

       Marine Data                   Inline Geom
       SSD correction                Header Load      Valid Trace
                                                      Numbers
                                                      Overwrite              Seismic Data
          Seismic Data                                Trace Headers
           (ProMAX)                                                           (ProMAX)
                           The full extraction process makes one very critical assumption in that
                           there must be some unique trace header value for all traces of the same
                           shot and receiver. That is, there must be unique source and receiver
                           position numbers, FFIDs, Coordinates, or Date/Time stamps in addition
                           to the recording channel numbers.




3-2             ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                         Chapter 3: Database from Geometry Extraction




Overview of the Exercise
             In this exercise you will read two SEGY files that contain most of the
             geometry information in their trace headers. Each file contains the shots
             for one half of the Manhattan 3D project. You will read one SEGY file,
             extract the information and complete the database. You will then read
             the second file and append it’s information to the same database.
             This gets tricky on this project since you are processing the Right hand
             side of the survey first. You must first decide how you want your lines
             and crosslines to be numbered.

             In this case we will assume that you want your minimum crossline on
             the South and the minimum inline on the East. This will mean that you
             will be able to expand the grid to the West as the other half of the data
             becomes available. You will simply add more lines to the survey at that
             time.
                                                      populated after the
                                                      first extraction




                                                                      inline 1
                                                                      xline 1

                             Population After 1st Half Extraction




Landmark                       ProMAX 3D Seismic Processing and Analysis           3-3
Chapter 3: Database from Geometry Extraction


                          After loading the second half of the data, the entire subsurface grid will
                          be populated.


       Population after 2nd Half Extraction
                                                                    populated after the
                                                                    second extraction




                                                                                      inline 1
                                                                                      xline 1




3-4            ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                  Chapter 3: Database from Geometry Extraction




Read and Extract the First SEGY File

                     In this exercise, you will read a SEGY file and extract the geometry
                     from the headers to build a database.


      Create a New Line and Run the First Extraction
                     1. Since you are going to create a new database, the first thing you need
                        to do is to create a new line in your area. This line will be another
                        copy of the Manhattan3d Project built using Full Extraction. Enter a
                        a line name similar to “Manhattan 3d - extraction.”

                     2. Build the following flow in your new line:

                    Editing Flow: 01 - extract 1st half

                    Add            Delete          Execute           View         Exit

                    SEGY Input
                          Type of storage to use: ----------------------------- Disk Image
                          Enter DISK file path name: -----------------------------------------
                                  --------------/misc_files/3d/manhattan_first_half
                          MAX traces per ------------------------------------------------240
                          Remap SEGY header values ---------------------------------Yes
                          Input/override trace header entries ----------------------------
                                  -----------------sou_sloc,,4I,,181/srf_sloc,,4I,,185/
                    Extract Database Files
                          Is this a 3D survey------------------------------------------------Yes
                          Data Type---------------------------------------------------------LAND
                          Source index method-------------------------------------------FFID
                          Receiver index method--------------------------------STATIONS
                          Mode of operation -----------------------------------OVERWRITE
                          Pre-geometry extraction?-----------------------------------------No
                          Extract CDP binning?----------------------------------------------No
                          Calculate trace midpoint coordinates?---------------------No
                          Extract OFB binning?----------------------------------------------No
                    Disk Data Output
                          Output Dataset FileName--------------shots-raw data (1st)


Landmark                               ProMAX 3D Seismic Processing and Analysis             3-5
Chapter 3: Database from Geometry Extraction


                          3. In the SEGY input read the file as described by your instructor

                              This will be the 1st half of the shots. There are 240 traces per
                              ensemble and you must remember to remap the SOU_SLOC and
                              SRF_SLOC values from the extended SEGY headers to the
                              ProMAX trace headers. In this menu the default values for
                              remapping SOU_SLOC and SRF_SLOC will work fine.

                          4. Remove the specification for the CDP_SLOC but make sure you
                             leave the last “/”.

                          5. Select the Extract Database Files parameters.

                              This is a Land 3D project where you will identify all traces coming
                              from a common source by their FFID number and all traces recorded
                              at the same receiver using the receiver station number. You will
                              overwrite any previous database information, if any, and do full
                              extraction instead of pre-geometry extraction. Do not extract the
                              CDP or OFB binning, this will be calculated and applied later.

                          6. In Disk Data Output, enter “shots - raw data (1st)” for a
                             new output file name.

                          7. Execute the flow.

                              Extract Database Files does all of the work. The program reads the
                              trace header information and establishes all of the necessary OPF
                              domains and their attributes. The dataset is then stamped with “valid
                              trace numbers”, permitting further processing with a consistent
                              pairing between the OPFs and the trace headers in the dataset.

                              (This is an important concept for the Inline Geom Header Load
                              process which will be run once the geometry is completed.)




3-6            ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                Chapter 3: Database from Geometry Extraction




Complete the Database for the First Half

      Land 3D Geometry Spreadsheet
                   The following steps complete the CDP binning and database
                   finalization. In this case we will look at the automatic CDP bin grid
                   generation procedures and also look at the CDP Binning* batch flow
                   process.

                   1. Build and execute the following flow:

                   Editing Flow: 02 - spreadsheet

                   Add            Delete         Execute          View        Exit

                   3D Land Geometry Spreadsheet

                   2. Select Setup from the main pull down menu options.




                   The setup menu allows you to define global information applying to the
                   configuration and operation of the Geometry Spreadsheet.

                   3. Select the Assign Midpoints Method of Existing index number
                      mappings in the TRC which is the default).

                         In the extract process, a shot and receiver location value and x,y
                         coordinate were extracted from each trace header. Every trace knows
                         which shot and receiver it belongs to so the binning can be done by
                         using existing values in the TRC ordered database file.




Landmark                              ProMAX 3D Seismic Processing and Analysis          3-7
Chapter 3: Database from Geometry Extraction


                                               Setup Window After Extraction




                          4. Enter 110’ for the nominal receiver station interval and crossline
                             separation and do not fill out the source station interval.

                              These numbers are only used for QC purposes.

                          5. Set the nominal survey azimuth to 5.6 degrees.

                          6. Answer No to Base Source station coordinates upon a match
                             between source and receiver station numbers.

                              In our case the sources are numbered 1001-1085 and the receivers
                              are 1-720. There is no relationship.

                          7. Select Shot holes for source type.

                          8. Set units to Feet



3-8            ProMAX 3D Seismic Processing and Analysis                               Landmark
                                                     Chapter 3: Database from Geometry Extraction


                    9. Do not specify reference coordinates.

                    10. Specify the font assignment of your choice.

                    11. Click OK.


      QC the Input with a Basemap
                    12. Open the Receivers Spreadsheet and generate a Basemap using the
                        View ¦ View All ¦ Basemap pull down menu.




                     Note:

                     Only the shots and receivers on the East side of the project exist on this map.




Landmark                                 ProMAX 3D Seismic Processing and Analysis                     3-9
Chapter 3: Database from Geometry Extraction


                          13. Use the Cross domain (double fold)icon to see which receivers are
                              defined as live for each shot.

                          14. Close the Basemap and the Receiver Spreadsheet windows.


       Trace Assignment
                          This exercise illustrates CDP binning procedures. For this example we
                          will automatically compute a CDP grid based on some initial known
                          values and then apply the grid using the batch CDP Binning* process.

                          1. In the main Geometry window, click Bin.

                              A submenu appears with options for Assigning the traces to
                              midpoints, defining the bin grid, binning the data, quality controlling
                              the binning, and finalizing the database.




                          2. Select Assign midpoints by using “Existing index number
                             mappings in the TRC, and click Ok.

                              In this case the Assignment step is performing the following
                              calculations:

                              •   Computes the Shot to Receiver Offset (Distance)

                              •   Computes the Midpoint coordinate between the shot and
                                  receiver.

                              •   Computes the Shot to Receiver Azimuth.




3-10           ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                    Chapter 3: Database from Geometry Extraction



                     Note:

                     Because we ran the full extraction, every trace already knows which shot and
                     receiver it contributes to.



                    3. An Assignment Warning window will pop up warning that some or
                       all of the data in the Trace spreadsheet will be overwritten. Click
                       Proceed.




                    4. A number of progress windows will flash on the screen as this step
                       runs. A final Status window should notify that you have
                       “Successfully completed geometry assignment.” Click Ok.


      Automatic Bin Calculation and QC
                    5. From the 3D Binning and QC window select Bin Midpoints.




Landmark                                ProMAX 3D Seismic Processing and Analysis                   3-11
Chapter 3: Database from Geometry Extraction


                          You should get the following window:




                          This window controls two binning operations:

                          • CDP subsurface Binning
                          • Offset Binning
                          Let’s worry about one binning operation at a time. First, let’s do the
                          CDP binning.


       CDP Bin Origin and Direction
                          ProMAX geometry assignment allows you to define your binning
                          parameters so any corner of the project can be the origin of the inline,
                          crossline and CDP numbering. You may also choose the inline and
                          crossline directions. There are three rules by which you must abide:

                          •   The Y axis is always parallel to the specified azimuth.




3-12           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                         Chapter 3: Database from Geometry Extraction


            •     The X axis is always 90 degrees clockwise from the Y axis.

            •     The grid cell X and Y dimensions must be input as positive
                  numbers.



                              o
                            45
                Azimuth __________
                                                o
                                Y
           Inline Parallel to ______          45

                  Y


                 X


                Inline 1
                Xline 1
                CDP 1



                                 Example of Bin Parameters 1




Landmark                       ProMAX 3D Seismic Processing and Analysis        3-13
Chapter 3: Database from Geometry Extraction




                                           o
                                        225
                            Azimuth __________
                                                             o                Inline 1
                                             X
                        Inline Parallel to ______          45                 Xline 1
                                                                              CDP 1

                                          X


                                      Y




                                                Example of Bin Parameters 2


                            Azimuth __________
                                       275.6
                        Inline Parallel to ______
                                             X
                                                           5.6o



                                                X
                                  Y

                                                    o
                                               275.6
                                                                               Inline 1
                                                                               Xline 1
                                                                               CDP 1


                                                        This Case



3-14           ProMAX 3D Seismic Processing and Analysis                         Landmark
                                     Chapter 3: Database from Geometry Extraction


           6. In the 3D Land Midpoint Binning window set Azimuth=275.6,
              Grid Sizes=55 in each direction, supply a Bin Space Name such as
              “Calculated CDP bins 55x55-origin in SE
              corner”.




           7. Click Calc Dim.

              The Calc Dim operation computes the origin of the grid and the
              maximum X and Y dimensions to yield the following:




Landmark                   ProMAX 3D Seismic Processing and Analysis        3-15
Chapter 3: Database from Geometry Extraction




                            Calculated




                          8. Save the grid definition by clicking Save.

                          9. Click Cancel to exit the window.


       QC, Edit and Save the CDP Binning Grid
                          1. Select Define binning grid from the main binning window and click
                             Ok.




                              This will bring up a small map window (without the map).




3-16           ProMAX 3D Seismic Processing and Analysis                             Landmark
                                   Chapter 3: Database from Geometry Extraction


           2. Select Display ¦ Midpoint ¦ Control Points ¦ Black
              (depending on the color of the background).




Landmark                  ProMAX 3D Seismic Processing and Analysis       3-17
Chapter 3: Database from Geometry Extraction


                          You should get the following display:




                                         Midpoint Scattergram for CDP Binning

                          3. Select Grid ¦ Open and the grid name that you saved from the
                             Calc Dim operation.




3-18           ProMAX 3D Seismic Processing and Analysis                           Landmark
                                    Chapter 3: Database from Geometry Extraction


           This step overlays the bin grid on your subsurface data.




                                                                       X marks
                                                                       grid
                                                                       origin




                          Scattergram with Grid Overlay

           The computed grid exactly overlays the existing subsurface
           coverage. Notice that this grid is 26 lines with 78 bins per line. We
           need to prepare ourselves for the extension of the project when the
           data becomes available. According to the supplier of the data we will
           eventually have 42 lines with 79 CDP’s per line. The first line is on
           the East and does not pose a problem since we can simply add more
           lines to the grid. The problem is that we do not know if we need to
           add the extra bin on the north or south to size the grid at 79 bins per



Landmark                 ProMAX 3D Seismic Processing and Analysis            3-19
Chapter 3: Database from Geometry Extraction


                              line. We can make an educated guess by looking at the basemap of
                              the entire proposed project and expand the grid as required.
                          4. In order to figure this out we will have to refer back to a master
                             Basemap that was provided by the supplier of the data.



                                                                                                 X




                    Y




                                                  Total Project Basemap

                              From this map we will have to decide whether the shots on the
                              North-East or the South-West are further away from the cable lines.
                              From this map it appears that the distance Y is greater than the
                              distance X which implies that we need to add at least one additional
                              crossline to our grid on the South.




3-20           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                      Chapter 3: Database from Geometry Extraction


           5. The easiest way to add the crossline at the South is to use the Add
              or Delete cells icon.




                            Additional Grid Cell on the South

           6. Add a cell at the South by clicking MB1 (“add a cell”) near the
              south edge of the existing grid.

           7. You may also elect to do some selective zooming in combination
              with the Grid ¦ Drawing functionality to carefully position the
              grid so the midpoints are centered in the cells.




Landmark                    ProMAX 3D Seismic Processing and Analysis           3-21
Chapter 3: Database from Geometry Extraction


                          8. Save your edited using the Grid ¦ Save to pull down menu.




                          9. Enter a new grid name and click the Ok.

                          10. Exit the XYgraph display using the File ¦ Exit ¦ Confirm pull
                              down menu.




3-22           ProMAX 3D Seismic Processing and Analysis                           Landmark
                                                     Chapter 3: Database from Geometry Extraction


      Reload the edited CDP Grid and Complete CDP Binning
                    1. Return to the 3D Land Midpoint Binning Window and select Load
                       to bring back your edited grid.




                     Note:

                     The Offset Bin increment and the Inlines parallel to grid axis have been reset.




Landmark                                 ProMAX 3D Seismic Processing and Analysis                     3-23
Chapter 3: Database from Geometry Extraction


       Finalize the Offset Binning and CDP Bin Direction Parameters
                          1. Set the Min offset to bin=0, Offset binning increment to 110 ft and
                             select Inline to be parallel to the X axis (perpendicular to azimuth).




                          2. Click Apply to perform the Binning.

                          3. When complete, dismiss the notification window and click Cancel.




3-24           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                               Chapter 3: Database from Geometry Extraction


      Generate a Fold QC Plot and Finalize the Database
                     1. Return to the 3D Binning and QC window and select QC Bin data,
                        select your grid for the QC Bin space and click Ok.




                     2. This should generate a QC fold plot that shows live CDPs on the
                        northern most crossline and zero fold CDPs in the south.




                                                                                  Live
                                                                                  CDPs




                            Zero
                            Fold
                            CDPs




Landmark                              ProMAX 3D Seismic Processing and Analysis       3-25
Chapter 3: Database from Geometry Extraction


                          3. Exit the XYgraph display using the File ¦ Exit ¦ Confirm
                             pulldown menu.

                          4. Return to the 3D Binning and QC window and select Finalize the
                             database and click Ok.




                          5. When complete, dismiss the notification window and click Cancel.

                          6. Select File ¦ Exit from the main geometry spreadsheet window to
                             exit.




3-26           ProMAX 3D Seismic Processing and Analysis                           Landmark
                                          Chapter 3: Database from Geometry Extraction




Load Geometry to the Trace Headers

            1. If the geometry in the database looks good, build the following flow:


            Editing Flow: 03 - load geom to headers

            Add            Delete          Execute           View        Exit

            Disk Data Input
                  Read data from other lines/surveys -----------------------No
                  Select Dataset-------------------------”shots - raw data (1st)”
                  Trace read option---------------------------------------------Get All
                  Read the data multiple times?---------------------------------No
                  Process trace headers only?------------------------------------No
                  Override input data’s sample interval ---------------------No
            Inline Geom Header Load
                  Match by valid trace number?--------------------------------Yes
                  Drop traces with NULL CDP headers?----------------------No
                  Drop traces with NULL receiver headers?-----------------No
                  Verbose Diagnostics?----------------------------------------------No
            Disk Data Output
                  Output Dataset Filename--------”shots - with geom (1st)”
                  New, or Existing, File?------------------------------------------New
                  Record length to output--------------------------------------------0.
                  Skip primary disk Storage?-------------------------------------No

            2. In Disk Data Input, enter your input dataset that contains the shots
               for the first half of the project.

            3. In Inline Geom Header Load, match the traces by their “valid trace
               numbers”.

                  Since the traces were read and counted with Extract Database Files,
                  you have a “valid trace number” to identify a trace. You have binned
                  all traces; therefore, do not drop any traces. Unless you have a
                  problem, there is no need for verbose diagnostics.

            4. In Disk Data Output, output a new dataset.



Landmark                        ProMAX 3D Seismic Processing and Analysis          3-27
Chapter 3: Database from Geometry Extraction


                          5. Execute this flow.

                          6. After the flow has completed, go to the datasets list and press MB2
                             on the file name.

                              The dataset should now reflect that both the geometry and trace
                              numbers match the database.




3-28           ProMAX 3D Seismic Processing and Analysis                              Landmark
                                                 Chapter 3: Database from Geometry Extraction




Append the Second SEGY File

      Run the Second Extraction
                    In this exercise, we will read another SEGY file and extract the
                    geometry from the headers to append to the existing database.

                    1. Copy and edit your first extraction flow to build the following flow:


                   Editing Flow: 04 - extract 2nd half

                   Add            Delete          Execute           View         Exit

                   SEGY Input
                         Type of storage to use: ----------------------------- Disk Image
                         Enter DISK file path name: -----------------------------------------
                                 ---------/misc_files/3d/manhattan_second_half
                         MAX traces per ensemble: ------------------------------------240
                         Remap SEGY header values ---------------------------------Yes
                         Input/override trace header entries ----------------------------
                                 -----------------sou_sloc,,4I,,181/srf_sloc,,4I,,185/
                   Extract Database Files
                         Is this a 3D survey------------------------------------------------Yes
                         Data Type---------------------------------------------------------LAND
                         Source index method-------------------------------------------FFID
                         Compare sources to previously extracted sources?:--No
                         Receiver index method--------------------------------STATIONS
                         Mode of operation ----------------------------------------APPEND
                         Pre-geometry extraction?-----------------------------------------No
                         Extract CDP binning?----------------------------------------------No
                         Calculate trace midpoint coordinates?---------------------No
                         Extract OFB binning?----------------------------------------------No
                   Disk Data Output
                         Output Dataset FileName------------shots-raw data (2nd)

                    2. In the SEGY Input read the file as described by your instructor.




Landmark                              ProMAX 3D Seismic Processing and Analysis            3-29
Chapter 3: Database from Geometry Extraction


                          This will be the 2nd half of the shots. There are 240 traces per ensemble
                          and you must remember to remap the SOU_SLOC and SRF_SLOC
                          values from the extended SEGY headers to the ProMAX trace headers.
                          In this menu the default values for remapping SOU_SLOC and
                          SRF_SLOC will work fine.

                          3. Remove the specification for the CDP_SLOC but make sure you
                             leave the last “/”.

                          4. Select the Extract Database Files parameters.

                              This is a Land 3D project where you will identify all traces coming
                              from a common source by their FFID number and all traces recorded
                              at the same receiver using the receiver station number.

                              In this execution we will Append the new information to an existing
                              database, and do full extraction instead of pre-geometry extraction.

                          5. In Disk Data Output, enter “shots - raw data (2nd)” for a
                             new output file name.

                          6. Execute the flow.




3-30           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                               Chapter 3: Database from Geometry Extraction




Complete the Database for the Second Half

      Land 3D Geometry Spreadsheet
                   The following steps complete the CDP binning and database
                   finalization. In this case the final CDP Binning Grid exists already but
                   it will need to be expanded. We will use the CDP Binning* batch flow
                   process to apply the binning and finalize the database.

                   1. Re-execute the spreadsheet flow:

                   Editing Flow: 02 - spreadsheet

                   Add          Delete          Execute          View        Exit

                   3D Land Geometry Spreadsheet




Landmark                             ProMAX 3D Seismic Processing and Analysis         3-31
Chapter 3: Database from Geometry Extraction


       QC the Input with a Basemap
                          2. Open the Receivers Spreadsheet and generate a Basemap using the
                             View ¦ View All ¦ Basemap pull down menu.




                           Note:

                           All of the shots and receivers for the entire project now exist on this map.



                          3. Use the “double fold” or “cross domain” icon to see which
                             receivers are defined as live for each shot.

                          4. Close the Basemap and the Receiver Spreadsheet windows using
                             the File ¦ Exit ¦ Confirm and File ¦ Abort pull downs
                             respectively.




3-32           ProMAX 3D Seismic Processing and Analysis                                              Landmark
                                                 Chapter 3: Database from Geometry Extraction


      Trace Assignment
                   1. In the main menu, click Bin.




                         A dialog box appears with options for Assigning the traces to
                         midpoints, defining the bin grid, binning the data, quality controlling
                         the binning, and finalizing the database.




                   2. Select Assign midpoints by: Existing index number mappings in
                      the TRC, and click Ok.

                         In this case the Assignment step is performing the following
                         calculations:

                         •   Computes the Shot to Receiver Offset (Distance)

                         •   Computes the Midpoint coordinate between the shot and
                             receiver.

                         •   Computes the Shot to Receiver Azimuth.




Landmark                               ProMAX 3D Seismic Processing and Analysis          3-33
Chapter 3: Database from Geometry Extraction



                           Note:

                           Because we ran the full extraction, every trace already knows which shot and
                           receiver it contributes to.

                           The assignment step also re-assigns all traces, it does not know about the APPEND
                           action that we performed.



                              An Assignment Warning window will pop up warning that some or
                              all of the data in the Trace spreadsheet will be overwritten. Click
                              Proceed.




                              A number of progress windows will flash on the screen as this step
                              runs. A final status window should notify that you successfully
                              completed geometry assignment. Click Ok.

                              If this step fails, you have an error in your spreadsheets somewhere.
                              Not much help is given to you, but the problems are usually related
                              to the spread and/or pattern definitions.


       Expand the CDP Binning Grid
                          In this sequence we need to add more lines to the existing CDP grid. We
                          need to make sure that we do not alter the X-Y coordinates of the
                          previously existing bins by rerunning the Calc Dim. If we did this we
                          would probably change the bin centers which would invalidate the
                          geometry loaded to the first half trace headers.

                          Part of the strategy here is to avoid having to reload the geometry to the
                          first half. By simply adding lines to the bin grid we are not changing the
                          trace numbers, SIN, SRF, CDP, ILN, XLN, OFB or any other attribute
                          of the traces that have already been processed.




3-34           ProMAX 3D Seismic Processing and Analysis                                          Landmark
                                     Chapter 3: Database from Geometry Extraction


           1. Select Define binning grid from the main binning window and click
              Ok.




              This will bring up a small map window.

           2. Select Display ¦ Midpoint ¦ Control Points ¦ Black
              (depending on the color of the background).




Landmark                   ProMAX 3D Seismic Processing and Analysis        3-35
Chapter 3: Database from Geometry Extraction


                          You should get the following plot:




                                        Mid-point Scattergram for CDP Binning

                          3. Select Grid ¦ Open and select the grid name that you saved as the
                             final CDP Binning Grid after manual editing.




3-36           ProMAX 3D Seismic Processing and Analysis                             Landmark
                                      Chapter 3: Database from Geometry Extraction


              This step overlays the bin grid on your subsurface data.




                                    Half Grid Overlay

              The grid covers the Eastern part of the survey but must be extended
              to cover the entire survey

           4. Click the Modify the number of grid cells icon and move your
              mouse cursor to the western edge of the project.

           5. Click MB2 and watch the grid extend to the cursor.

           6. Add or delete cells as required.




Landmark                    ProMAX 3D Seismic Processing and Analysis        3-37
Chapter 3: Database from Geometry Extraction


                              The final grid should be at an azimuth of 275.6 degrees and have 79
                              cells in the X direction and 42 in the Y direction. The cells should be
                              55 ft in each direction.

                          7. Save the grid from the XYgraph window using the Grid ¦ Save to
                             pulldown menu.




                          8. Enter a new grid name and click Ok.

                          9. Exit from the XYgraph by selecting File ¦ Exit ¦ Confirm.




3-38           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                  Chapter 3: Database from Geometry Extraction


                      10. Select Bin midpoints and click Ok from the 3D Binning and QC
                          window.




                                                         12
                 11




                      11. Load the grid for the entire project, and reset the offset binning and
                          inlines parallel to the grid X axis parameters.

                      12. Click Save to save the edited grid information and then click
                          Cancel.

                      13. Close the 3D Binning and QC window by clicking Cancel.

                      14. Select File ¦ Exit from the main spreadsheet menu to exit the
                          Geometry Spreadsheet.


      Complete CDP Binning using the Batch CDP Binning Tool
                      This exercise completes the CDP binning and database finalization
                      steps.




Landmark                                ProMAX 3D Seismic Processing and Analysis           3-39
Chapter 3: Database from Geometry Extraction


                          1. Build the following flow:


                         Editing Flow: 05 - CDP Binning

                         Add            Delete          Execute          View        Exit

                         CDP Binning*
                               Binned Space Name ------------------------ “your grid”

                          2. Select the grid you created for the entire project.

                          3. Execute the flow.

                               This process will perform the CDP binning and Finalization steps in
                               a batch job instead of interactively using the Geometry spreadsheet.

                          4. When the binning flow completes, generate a QC plot from
                             DBTools by selecting View ¦ Predefined ¦ CDP fold map.




3-40           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                      Chapter 3: Database from Geometry Extraction


              The fold plot should now be fully populated.




           5. Click on the 0 fold bar in the histogram to display the CDPs with
              zero fold.

           6. From the DBTools display select View ¦ Close and then
              Database ¦ Exit.




Landmark                    ProMAX 3D Seismic Processing and Analysis        3-41
Chapter 3: Database from Geometry Extraction




Load Geometry to the Trace Headers

                          1. After the binning is complete, edit the existing flow:


                         Editing Flow: 03 - load geom to headers

                         Add            Delete          Execute           View        Exit

                         Disk Data Input
                               Read data from other lines/surveys -----------------------No
                               Select Dataset------------------------”shots - raw data (2nd)”
                               Trace read option---------------------------------------------Get All
                               Read the data multiple times?---------------------------------No
                               Process trace headers only?------------------------------------No
                               Override input data’s sample interval ---------------------No
                         Inline Geom Header Load
                               Match by valid trace number?--------------------------------Yes
                               Drop traces with NULL CDP headers?----------------------No
                               Drop traces with NULL receiver headers?-----------------No
                               Verbose Diagnostics?----------------------------------------------No
                         Disk Data Output
                               Output Dataset Filename---------”shots-with geom(2nd)”
                               New, or Existing, File?------------------------------------------New
                               Record length to output--------------------------------------------0.
                               Skip primary disk Storage?-------------------------------------No

                          2. In Disk Data Input, enter your input shot dataset that contains the
                             shots for the second half of the project.

                          3. In Inline Geom Header Load, match the traces by their “valid trace
                             numbers”.

                               Since the traces were read and counted with Extract Database Files,
                               you have a “valid trace number” to identify a trace. You have binned
                               all traces; therefore, do not drop any traces. Unless you have a
                               problem, there is no need for verbose diagnostics.

                          4. In Disk Data Output, output to a new dataset.



3-42           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                      Chapter 3: Database from Geometry Extraction


           5. Execute this flow.

           6. After the flow has completed, go to the datasets list and press MB2
              on the file name.

              The dataset should now reflect that both the geometry and trace
              numbers match the database.




Landmark                    ProMAX 3D Seismic Processing and Analysis        3-43
Chapter 3: Database from Geometry Extraction




Exercise Summary

                          The following points are important to note:

                          •   The first extraction was run in Overwrite mode.

                          •   The CDP grid was defined to cover the existing project area.

                          •   Since we ran the extraction and output a dataset we could load the
                              geometry by existing “valid trace numbers.”

                          •   The second extraction was run in Append mode.

                          •   We expanded the CDP grid after the second extraction making sure
                              not to alter the grid that was used for the first extract except to add
                              bins for the new inlines.

                          •   The second geometry assignment had no knowledge of the append
                              and therefore reassigned all traces in the database.

                          •   After running the second assignment step we have to completely
                              rebuild the Trace database. The dataset for the first half, however
                              still matches the database because we did not change the trace
                              numbers, SIN, SRF, CDP, ILN XLN, or OFB that the traces from
                              the first half contribute to. All we did was add new traces.

                          •   After the second execution of the Inline Geom Header Load we
                              now have two separate datasets, or Superswaths that we can use to
                              continue processing.




3-44           ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                 Chapter 3: Database from Geometry Extraction




Full Extraction

                     In the previous exercise, our trace data headers did not contain binning
                     information so we had to use the Geometry Spreadsheet to create it.
                     However, if you receive data with trace headers that include:

                     •   Source X, Y coordinates and station number,
                     •   Receiver X, Y coordinates and station number,
                     •   CDP X, Y and CDP number,
                     •   Iline and Xline numbers, and
                     •   Offset bin number,

                     you can use the Extract Database Files tool to automatically build the
                     CDP, ILN, XLN and OFB orders. We refer to datasets with this
                     information as having “fully-populated trace headers.”

                     Once the Extract flow is complete, you will still need to open the LIN
                     ordered database file editor, unlock the protected fields, and complete
                     the Binning Parameters section. It may be helpful to generate an
                     XYGraph display of CDP: X_Coord, Y_Coord, and Fold from XDB
                     Database Display and use the Grid option to get the azimuth and
                     coordinate information.

                     Since the geometry information is already in the trace headers, you will
                     not need to run Inline Geometry Header Load if you write a new file
                     after the Extraction. This output file is automatically stamped as
                     matching the database.

                     This approach is best suited to datasets that have been previously
                     processed in ProMAX but can also be used on SEG- ? formatted data if
                     the trace headers are remapped properly during input.

                     In this exercise, you will read an existing ProMAX format file and
                     extract the geometry from the headers to build a database.


      Create a New Line and Run the First Extraction
                     1. Since you are going to create a new database, the first thing you need
                        to do is to create a new line in your area. This line will be another




Landmark                              ProMAX 3D Seismic Processing and Analysis           3-45
Chapter 3: Database from Geometry Extraction


                               copy of the Manhattan3d Project built using Full CDP Extraction.
                               Enter a a line name similar to “Full CDP Extraction.”

                          2. Build the following flow in your new line:


                         Editing Flow: 01 - extraction

                         Add            Delete          Execute           View         Exit

                         Disk Data Input
                               Read data from other lines/surveys ----------------------Yes
                               Select Dataset------------------------”shots - with geom (1st)”
                               Trace read option---------------------------------------------Get All
                               Read the data multiple times?---------------------------------No
                               Process trace headers only?------------------------------------No
                               Override input data’s sample interval ---------------------No
                         Extract Database Files
                               Is this a 3D survey------------------------------------------------Yes
                               Data Type---------------------------------------------------------LAND
                               Source index method-------------------------------------------FFID
                               Receiver index method--------------------------------STATIONS
                               Mode of operation -----------------------------------OVERWRITE
                               Pre-geometry extraction?-----------------------------------------No
                               Extract CDP binning?---------------------------------------------Yes
                               Minimum cdp bin in survey --------------------------------------1
                               Calculate trace midpoint coordinates?---------------------No
                               Extract OFB binning?----------------------------------------------No

                          3. Read the first half trace data file from your “full extraction” line
                             after geometry load. (Shots -with geom (1st))

                          4. Extract all available information in the headers by specifying that
                             this is a Land 3D project where you will identify all traces coming
                             from a common source by their FFID number and all traces
                             recorded at the same receiver using the receiver station number.
                             You will overwrite any previous database information, if any, and
                             do full extraction instead of pre-geometry extraction. Extract the
                             CDP numbers from the headers but do not compute midpoint
                             coordinates.




3-46           ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                               Chapter 3: Database from Geometry Extraction


      Edit the LIN Database
                     After the extraction has completed, open DBTools by clicking on
                     Database.

                     1. From the DBTools main window , select View ¦ Lin

                     2. From the LIN editor main window , select Database ¦ Lock
                        protected fields




                     3. Notice that the CDP, SIN, SRF, and TRC counts are accurate.




Landmark                              ProMAX 3D Seismic Processing and Analysis        3-47
Chapter 3: Database from Geometry Extraction


                          4. Scroll to the bottom of the LIN Database Editor window and notice
                             that all of the grid parameterization is NULL’ed. You will need to
                             enter this information manually.




                          The Grid information is essential to process these data through
                          processes such as Stack3D, 3DDmo and 3D Migration, as well as
                          velocity field processing.




3-48           ProMAX 3D Seismic Processing and Analysis                              Landmark
                                                Chapter 3: Database from Geometry Extraction




Processing without a Database

                    Running geometry to build a database can be a time consuming step
                    especially in large-volume marine processing. Extracting all the
                    geometry information from the trace headers and automatically building
                    the database saves a time but still results in very large database files
                    being stored. To avoid these problems, ProMAX supports processing
                    without building a full database.

                    While valid geometries and the corresponding databases will still be
                    needed for surface consistent tools land tools like statics, many
                    ProMAX processes are designed so they either do not require a database
                    at all or just a minimal LIN database.

                    In versions prior to 7.0, ProMAX used the database to interpolate tables.
                    Starting with in ProMAX 7.0, the table interpolation routines were
                    changed to utilize (x,y) coordinates from the data trace headers instead
                    of only retrieving them from the database. This change allows ProMAX
                    a much greater degree of database-independent processing.

                    Tools which import or manipulate CDP-ordered tables, such as Velocity
                    Analysis, will still need a minimal database consisting of the LIN
                    Ordered Parameter File (OPF) with Inline and Crossline numbering,
                    CDPs and the grid parameters in order to define the extents of the 3D
                    survey. As we learned in the previous section, the LIN database can be
                    built using the DBTools editing features with much less time and effort
                    than assigning geometry and building a full database.


      Minimal Database
                    The LIN OPF entries required in a minimal database are:

                      Entry                                              Attribute Name

                      3-D flag                                            I3Dz

                      Marine flag                                         IMARINEz

                      Minimum CDP number                                 MINCDPz

                      Maximum CDP number                                 MAXCDPz

                      CDP number increment                               INCCDPz

                      Number of inlines (3D)                             NILINESz



Landmark                               ProMAX 3D Seismic Processing and Analysis        3-49
Chapter 3: Database from Geometry Extraction


                            Entry                                                Attribute Name

                            Number of crosslines (3D)                            NXLINESz

                            Minimum inline number (3D)                           MINILINz

                            Maximum inline number (3D)                           MAXILINz

                            Distance between CDPs in inline direction (3D)       DCDPILNz

                            Minimum crossline number (3D)                        MINXLINz

                            Maximum crossline number (3D)                        MAXXLINz

                            Distance between CDPs in crossline direction (3D)    DCDPXLNz

                            X origin of 3D grid                                  X3DORIGz

                            Y origin of 3D grid                                  Y3DORIGz

                            X coord of far end of first inline                    XILNENDz

                            Y coord of far end of first inline                    YILNENDz



                          ProMAX will attempt to resolve (x,y) coordinates in the following
                          sequence: First, it will look for a valid (x,y) coordinates in the trace
                          headers. If that fails, it will attempt to resolve (x,y) using the LIN-
                          ordered parameter file. Finally, it will revert to looking up (x,y) in the
                          database.

                          Most ProMAX tools only need a minimal database in addition to the
                          (x,y) coordinates in the trace headers. If none of the LIN parameters
                          have been defined, only tables with primary keys other than CDP can be
                          created manually or picked interactively and they will be interpolated
                          linearly based on the primary key. If the 3D flag is set in the LIN OPF,
                          tables with primary keys other than CDP can be picked interactively and
                          will resolve (x,y) coordinates from the data trace headers yielding true
                          x,y interpolation. Once the LIN parameters have been defined in the
                          limited database, CDP-ordered tables will be interpolated with true x,y
                          positions.




3-50           ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                           Chapter 3: Database from Geometry Extraction


Full Database
                The following tools require a full and complete database:

                 Geometry                      Database/Header Compare
                                               Merge Database Files
                                               Database/Header Transfer
                                               Database Parameter Merge
                                               CDP Taper
                                               Assign CDP Flex Binning
                                               Expand Flex Binning
                                               Inline Geom Header Load
                                               Graphical Geometry QC
                                               Source Receiver Geom Check

                 Editing/Muting/Noise          NN Trace Editor Training
                                               NN Reversed Trace Training
                                               NN Trace Editor
                                               NN Reversed Trace Editor
                                               Trace Statistics (unless run on “Headers
                                               Only”)
                                               Ensemble Statistics

                 Amplitude/AVO                 Surface Consistent Amplitudes

                 Statics                       Apply Elevation Statics
                                               Datum Statics Calculation
                                               Datum Statics Apply
                                               Apply User Statics




Landmark                          ProMAX 3D Seismic Processing and Analysis               3-51
Chapter 3: Database from Geometry Extraction


                            Refraction/Residual Statics    Apply Refraction Statics
                                                           Apply Residual Statics
                                                           Apply Trim Statics
                                                           First Break Picking (unless run on “Headers
                                                           Only”)
                                                           NN First Break Picker
                                                           3D Ref Statics Model
                                                           Refraction Statics Calculation
                                                           3D Reflection Correlation Autostatics
                                                           3D Ref Statics Inversion
                                                           3D Ref Statics Computation
                                                           External Model Correlation
                                                           Solve Integrated Statics
                                                           EMC Autostat: Gauss-Seidel
                                                           EMC Autostat: Xcor Sum
                                                           2D/3D Max. Power Autostatics

                            Deconvolution                  Surface Consistent Decon



                            Display                        Database To Zycor ASCII
                                                           Make Database Basemap
                                                           Contour Database Parameter
                                                           View Database Basemap

                            Miscellaneous                  NN Horizon Picker Training
                                                           Database/Horizon Transfer
                                                           NN Horizon Picker




3-52           ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                                              Chapter 4
                              Processing Sequence Flow
Before starting a processing project it is important to plan the proposed steps. In this chapter we
will outline the proposed processing steps and analyze the input requirements for those steps. We
will plan our flow to minimize the number of times we have to read the data and try to make all of
the flows that we prepare as efficient as possible.




Topics covered in this chapter:

                          t Main Process Flow
                          t Detailed Process Flow - Trace Processing
                          t Detailed Process Flow - DMO and Velocity Analysis
                          t Detailed Process Flow - DMO stack and Migration




Landmark                                     ProMAX 3D Seismic Processing and Analysis          4-1
Chapter 4: Processing Sequence Flow




Main Process Flow


                                       Geometry
          full extraction             complete database                load geometry




                                 Trace Processing
                      preprocessing                      brute stack



                      refraction statics                refr stat stack



                      residual statics                 resid stat stack


                                      velocity analysis




                                         Imaging
                                         dip moveout



                                         final stack


                                           migration




4-2           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                         Chapter 4: Processing Sequence Flow




Detailed Process Flow - Trace Processing


           Pre-stack data                                  Pre-stack data
    4 ms    with geom                                     with pre-processing 4 ms
    16 bit                                                                    16 bit
       pre-processing flow                                     brute stack flow


            Pre-stack data
    4 ms     with geom
    16 bit
       Pick first
      break times



                                                          Pre-stack data
           first arrival times                           with pre-processing 4 ms
                                                                             16 bit
       refraction statics flow                        refraction statics stack flow



               Stack data with
    4 ms   refraction statics applied
    16 bit                                          stack
     Build External Model flow

                                                 pre-stack with NMO
              External Model                     bandpass filter and AGC
   8 ms
   8 bit
           Correlation Time Gate

         Pre-Stack data with
   8ms NMO and refraction                              Pre-stack data with
   8 bit statics applied                            refraction statics applied 4 ms
                                                                               16 bit
      residual statics flow                           residual statics stack flow




Landmark                                ProMAX 3D Seismic Processing and Analysis       4-3
Chapter 4: Processing Sequence Flow




Detailed Process Flow - DMO and Vel-Anal

                                                           Pre-stack data with
                                                        refraction statics applied 4 ms
                                                                                   16 bit
                                                         residual statics stack flow
                  Pre-stack data with final
       8 ms       statics, bandpass and AGC
       8 bit      (data on vel lines only)
                                                               ? what is my velocity
                  Velocity Analysis flow                        analysis supergather
                      before DMO                                   geometry ?
                                                               Offset Distribution
                                                                   Analysis


                                                          Pre-stack data with     4 ms
                                                       refraction statics applied 16 bit

                                                      Final Velocities before DMO
                                                              Prepare data for
                                                             3D DMO To Gathers

       4 ms      Pre-stack data with final
       16 bit    statics, NMO and MUTE
               DMO to Gathers, and
        Inverse NMO on the velocity lines



                Pre-stack data with final
      8 ms      statics, NMO, MUTE, DMO
      8 bit     inverse NMO, BP and AGC
                   (data on vel lines only)
                 Velocity Analysis flow
                       after DMO




4-4              ProMAX 3D Seismic Processing and Analysis                             Landmark
                                                        Chapter 4: Processing Sequence Flow




Detailed Process Flow - DMO Stack and Migration



                                                 Pre-stack data with
                                              refraction statics applied 4 ms
                                                                         16 bit
                                               Final Dip independent
                                               RMS Velocity Field
                                                    Prepare data for
                                                      Stack DMO



     4 ms Pre-stack data with final
     16 bit statics, dip independent
            NMO and MUTE

              DMO to Stack 3D flow




                                                    Final Dip Independent
                                                    RMS Velocity Field
                                                       Velocity Model
                                                       Conditioning for
                                                       Migration


                Stack with final
     4 ms       statics, velocities,
     16 bit     and DMO applied

               Migration Velocities
                Migration flow




Landmark                               ProMAX 3D Seismic Processing and Analysis       4-5
Chapter 4: Processing Sequence Flow




4-6           ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                            Chapter 5
                       Preprocessing and Elevation
                                            Statics
Both 2D and 3D land data need prestack processing and datum statics. This chapter presents a
review of typical prestack processing, including top mute, true amplitude recovery, deconvolution
filter and elevation statics.




Topics covered in this chapter:

                          t Top Mute and Decon Design Gate Picking
                          t Decon Test and Interactive Spectral Analysis
                          t Datum Statics Calculation and Application
                          t Super Swath Processing Strategies
                          t Preprocessing Flows




Landmark                                    ProMAX 3D Seismic Processing and Analysis         5-1
Chapter 5: Preprocessing and Elevation Statics




Top Mute and Decon Design Gate Picking

                           The preprocessing flow that you will build uses processes requiring
                           parameter tables. For example, you will need to apply a first break
                           suppression mute and deconvolution. Therefore, you must pick a top
                           mute and a miscellaneous time gate (decon design gate) from a few shot
                           records.

                           Since 3D shot records usually span multiple cables, they will typically
                           have some duplicate offsets. Sorting the shot record by offset may help
                           pick the parameter tables, since both tables are usually time values,
                           interpolated as a function of offset. It may help to display the traces with
                           variable trace spacing as a function of offset.


        Identifying Analysis Locations
                           You will need to determine which shots to use when you pick your
                           tables and check the need for space variance. You can generate a map of
                           the shot locations and pick a few shots based on their SOURCE
                           numbers.

                           This introduces a major difference between ProMAX 2D and 3D. In
                           ProMAX 3D all parameter tables are interpolated based on their X and
                           Y locations. In ProMAX 2D all interpolation is done linearly by primary
                           sort key.

                           Another issue here is that you may end up having to read many tapes to
                           capture the shots of interest. In this flow we will output a dataset with
                           just the selected shots. This dataset will come in handy several times
                           during the course of the processing exercise. We will use the dataset to
                           pick the parameter tables, train the neural network and as input to the
                           Datum Statics Apply flows.

                           Having a few shot records immediately available on disk will be a
                           valuable resource and make parameter testing run much faster.

                           1. From the line level, click Database to bring up DBTools and
                              generate the following display from the SIN order:

                               Select View¦2D Matrix... from the DBTools main window
                               pulldown menu.




5-2            ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                      Chapter 5: Preprocessing and Elevation Statics


              When the Create 2D Crossplot Matrix attribute selection window
              appears, click the tab for the SIN order. Next, select the X_COORD,
              Y_COORD, SOURCE, SOURCE attributes and click OK..




                                                                        1014
                               1071




                                                       1067




                                 1081                                     1001




                           Shots for Parameter Table Picking

           2. Enable Sample Tracking and point to a few shots and note the their
              SOURCE numbers.



Landmark                    ProMAX 3D Seismic Processing and Analysis            5-3
Chapter 5: Preprocessing and Elevation Statics


                               You may elect to view 5 shots; one from each corner and one from
                               the center of the project. For example, use SOURCE numbers 1001,
                               1014, 1067, 1071 and 1081.




5-4            ProMAX 3D Seismic Processing and Analysis                              Landmark
                                                 Chapter 5: Preprocessing and Elevation Statics


      Pick a Top Mute and Miscellaneous Time Gate
                    1. Build the following flow:


                   Editing Flow: 06- Pick parameter tables

                   Add            Delete          Execute           View        Exit

                   Disk Data Input
                         Select dataset--------------------------”shots-with geom (1st)”
                         Trace Read Option------------------------------------------------Sort
                         Interactive Data Access?-----------------------------------------No
                         Select primary trace header entry------------------SOURCE
                         Select secondary trace header entry ----------------- CHAN
                         Sort order for dataset---1001,1014,1067,1071,1081:*/
                   Disk Data Insert
                         Select dataset-------------------------”shots-with geom (2nd)”
                         Trace Read Option------------------------------------------------Sort
                         Select primary trace header entry------------------SOURCE
                         Select secondary trace header entry ----------------- CHAN
                         Sort order for dataset --1001,1014,1067,1071,1081:*/
                   Disk Data Output
                         Output Dataset ---------------------------”shots - 5 test shots”
                   Disk Data Input
                         Select dataset------------------------------”shots- 5 test shots”
                         Trace Read Option------------------------------------------------Sort
                         Interactive Data Access?-----------------------------------------No
                         Select primary trace header entry------------------SOURCE
                         Select secondary trace header entry -------------- OFFSET
                         Sort order for dataset---1001,1014,1067,1071,1081:*/
                   Automatic Gain Control
                   Trace Display
                         Number of ENSEMBLES /screen -------------------------------5
                         Trace Display MODE ----------------------------------Grayscale

                    2. In Disk Data Input and Disk Data Insert, input your shot record
                       datasets for the first and second halves respectively.




Landmark                              ProMAX 3D Seismic Processing and Analysis            5-5
Chapter 5: Preprocessing and Elevation Statics


                                Sort the input based on Source Numbers with a secondary sort of
                                channel. Select a few shots around the project to QC the space
                                variance of the parameter picking tables.

                           3. Output a dataset to disk containing your five 5 shot records.

                           4. Reread the 5 test shots file sorting by OFFSET

                             Note:

                             In 3D, offset and Aoffset are equal since there are no negative offsets.



                           5. All parameters in the AGC can be defaulted.

                           6. Select to plot 5 shots and use the Grayscale color scheme in the
                              Trace Display.

                           7. Execute the flow.

                           8. Pick a first break suppression mute using the Picking ¦ Pick Top
                              Mute... pull down to remove the first arrivals.

                             Note:

                             Use one of the shots from the corners for picking since the middle shot only
                             contains half of the offsets. Project to the other shots and repick if required.




5-6            ProMAX 3D Seismic Processing and Analysis                                                 Landmark
                                      Chapter 5: Preprocessing and Elevation Statics


           9. Pick a miscellaneous time gate using the Picking ¦ Pick
              Miscellaneous Time Gates... pulldown to use as a time window for
              the deconvolution design gate.




                             Example Mute and Design Gate

           10. Exit and stop the flow by selecting File ¦ Exit/Stop.

           11. A window will pop up asking if you want to save the edits. Click
               Yes to save the mute and time gate that you just created.


Landmark                    ProMAX 3D Seismic Processing and Analysis           5-7
Chapter 5: Preprocessing and Elevation Statics




Decon Test and Interactive Spectral Analysis

                           Deconvolution testing may become very involved in certain situations.
                           One criterion that you may use to help decide on decon parameters is to
                           look at amplitude (or power) spectra of the trace data before and after
                           decon. If the decon has worked properly, you should see some
                           “flattening”, or “whitening” of the spectrum after decon relative to
                           before. In this exercise we will look at such a comparison on a single
                           shot record.




5-8            ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                  Chapter 5: Preprocessing and Elevation Statics


      Build a Flow to look at a power spectrum before and after decon
                     1. Build the following flow:


                    Editing Flow: 07- decon test and ISA

                    Add            Delete          Execute           View         Exit

                    Disk Data Input
                          Select dataset------------------------------”shots - 5 test shots”
                          Trace Read Option------------------------------------------------Sort
                          Select primary trace header entry--------------------------SIN
                          Select secondary trace header entry ----------------- CHAN
                          Sort order for dataset -------------------------------------------1:*/
                    Automatic Gain Control
                    Interactive Spectral Analysis
                          Data select method ----------------------------------------- Simple
                          Display data by traces or ensembles --------- Ensembles
                          ----- All remaining parameters may default -----




Landmark                               ProMAX 3D Seismic Processing and Analysis             5-9
Chapter 5: Preprocessing and Elevation Statics


                               You should get the following display:




                                        Interactive Spectral Analysis - Simple Mode

                               You can control the contents of the display by using the View ¦
                               Visibility pull down menu. You can then select the individual tiles
                               of interest.

                           2. Exit from the display using the File ¦ Exit/Stop Flow pull down
                              menu.

                           3. Edit the parameters for Interactive Spectral Analysis and select
                              Single Subset instead of Simple for the Data selection method.

                           4. Execute the flow again.




5-10           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                   Chapter 5: Preprocessing and Elevation Statics


           You should get the following display:




                Interactive Spectral Analysis - Single Subset Mode

           In this mode you can select a Single Subset of the available data for
           the purposes of computing the average power and phase specta.

           You can change your mind about the single subset as many times as
           you want to.




Landmark                 ProMAX 3D Seismic Processing and Analysis          5-11
Chapter 5: Preprocessing and Elevation Statics


                           5. Click on the Select Rectangular Region Icon and then draw a box
                              around an area of interest. The data window and spectral windows
                              will change configuration to match your data selection.




                           6. Exit from the display using the File ¦ Exit/Stop Flow pull down
                              menu.

                           7. Edit the parameters for Interactive Spectral Analysis and select
                              Multiple Subsets instead of Single Subset for the Data selection
                              method.

                               Also select Yes to Freeze the selected subsets.

                           8. Execute the flow again.




5-12           ProMAX 3D Seismic Processing and Analysis                               Landmark
                                   Chapter 5: Preprocessing and Elevation Statics


           You should get the following display:Interactive Spectral Analysis -
           Multiple Subset Mode




Landmark                 ProMAX 3D Seismic Processing and Analysis          5-13
Chapter 5: Preprocessing and Elevation Statics


                           9. Select the “Select Rectangular Region” icon and draw a box around
                              an area of interest and then select Options ¦ Spectral Analysis
                              from the pulldown menu.




                           10. If you select a new area and reselect Options ¦ Spectral Analysis,
                               a new window will appear. In this way you can compare the spectral
                               results for different areas.




5-14           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                          Chapter 5: Preprocessing and Elevation Statics


           11. Edit your flow to do a comparison before and after decon:


           Editing Flow: 07 - decon test and ISA

           Add            Delete           Execute           View          Exit

           Disk Data Input
                 Select dataset------------------------------”shots - 5 test shots”
                 Trace Read Option------------------------------------------------Sort
                 Select primary trace header entry--------------------------SIN
                 Select secondary trace header entry ----------------- CHAN
                 Sort order for dataset -------------------------------------------1:*/
           Automatic Gain Control
           Reproduce Traces
                 Trace grouping to reproduce ---------------------- Ensembles
                 Total number of datasets -----------------------------------------2
           IF
                 Trace Selection MODE-------------------------------------Include
                 SELECT Primary trace header word -------------- REPEAT
                 SPECIFY trace list ----------------------------------------------------1
           ELSEIF
                 Trace Selection MODE-------------------------------------Include
                 SELECT Primary trace header word -------------- REPEAT
                 SPECIFY trace list ----------------------------------------------------2
           Trace Muting
                 Select mute parameter file ---------------”first break mute”
           Spiking/Predictive Decon
                 Use all defaults except...
                 Select decon gate parameter file --------------”decon gate”
           ENDIF
           Interactive Spectral Analysis
                 Data select method ---------------------------Multiple Subsets
                 Freeze the selected subset? ----------------------------------Yes
                 Display data by traces or ensembles --------- Ensembles
                 ----- All remaining parameters may default -----

           12. After the spectral display appears select a region and use the
               Options ¦ Spectral Analysis pulldown menu to show the spectral
               estimate for the data before decon.

Landmark                       ProMAX 3D Seismic Processing and Analysis             5-15
Chapter 5: Preprocessing and Elevation Statics


                           13. Click on the Data ¦ Next Data pulldown menu to display the data
                               after decon.

                           14. Click the “Next Screen” icon and select the Analysis Options ¦
                               Spectral Analysis pull down menu again to show the spectral
                               estimate for the data after decon.

                               You can experiment with selecting subsets of the shot record before
                               and after decon. Notice how it remembers the selection window as
                               you change from one shot the next.




5-16           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                   Chapter 5: Preprocessing and Elevation Statics




Elevation Statics

                     Datum static corrections are generally required for land data to
                     compensate for adverse travel-time effects of topography and variations
                     in weathering thickness and velocity.

                     The process of calculating and applying datum statics within ProMaX
                     includes the following steps:

                     •   Compute static time shifts to take the seismic data from their
                         original recorded times, to a time reference as if the data were
                         recorded on a final datum (usually flat) using a replacement
                         velocity (usually constant).

                     •   Compute a floating datum (N_DATUM), a smoothed surface used
                         as the processing datum or NMO datum.

                     •   Partition the total statics into two parts, the Pre (before) NMO term
                         and Post (after) NMO terms relative to N_DATUM.

                     •   Apply the Pre (before) -NMO portion of the statics and write the
                         remainder to the trace header.

                     The first three steps occur in the calculation phase and the last step in the
                     apply phase. The calculation phase uses the your parameters in
                     combination with the information in the database and then results are
                     saved in the database. The apply phase reads the information from the
                     database and transfers it to the trace headers. ProMAX offers several
                     options for both phases; which option you should use depends on how
                     you are processing your data.


      Apply Elevation Statics
                     The first option is to simply add “Apply Elevation Statics” to your flow.
                     Apply Elevation Statics, despite its name both calculates and applies the
                     elevation statics. Because it both reads from and writes to the database,
                     which is shared amongst all the datasets within the Area/Line, you could
                     have a problem if you attempt to run more than one instance at the same
                     time. Therefore, if you are processing a large project in parts, as we are
                     for this training class, you will need to wait for Apply Elevation Statics
                     to complete before you run it again for the other datasets in your project.
                     When you run Apply Elevation Statics again for the additional dataset
                     parts, you will automatically recalculate the datum statics in the


Landmark                                ProMAX 3D Seismic Processing and Analysis            5-17
Chapter 5: Preprocessing and Elevation Statics


                           database for the entire project, even though you are only updating the
                           headers for the input dataset. In a large project, the time spent doing the
                           redundant datum statics calculation can be substantial especially if
                           combined with having to wait to get access to the database.


        Datum Statics Calculation and Datum Statics Apply
                           To help alleviate these problems, Apply Elevation Statics was split into
                           two separate modules, Datum Statics Calculation and Datum Statics
                           Apply.

                           In a typical workflow for large volume land processing, you would run
                           Datum Statics Calculation once to update the entire project database and
                           then run Datum Statics Apply for each dataset comprising the project.

                           Since Datum Statics Apply only reads the precalculated and saved
                           information in the database and transfers it to the trace headers, you
                           avoid repeating the calculation phase in Apply Elevation Statics so
                           processing time is saved and the possibility of having several flows
                           trying to write to the database at the same time is eliminated.

                           In addition, Datum Statics Calculation offers the ability to run multiple
                           times and save the output from each run under a unique Run ID. This
                           feature is handy when you wish to compare the results using different
                           parameters as we will do in the next exercise.

                           Before we begin the exercise, let us look at ProMAX datum statics
                           terminology and the calculation algorithms in more detail.


        Datum Statics Terminology
                           With ProMAX datum statics, you have the option to shift prestack data
                           to a floating datum or a final datum. You supply a final datum elevation
                           and a replacement velocity. The elev_stat_math file then establishes
                           values in the database for F_DATUM, N_DATUM, S_STATIC,
                           R_STATIC, and C_STATIC. Details of this process can best be
                           understood by examining the contents of the elev_stat_math file. This
                           file typically resides in $PROMAX_HOME/port/misc/elev_stat_math.

                           Elevation statics then creates three new header entries: NMO_STAT,
                           FNL_STAT, and NA_STAT. The integer multiple of a sample period
                           portion of NMO_STAT shifts traces to the floating datum in the apply
                           phase. The fractional sample period portion is written to the NA_STAT
                           header entry and applied later.



5-18           ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                       Chapter 5: Preprocessing and Elevation Statics


           If you select to process to a final datum, C_STATIC is set to zero. Since
           NMO_STAT = S_STATIC + R_STATIC + C_STATIC and
           C_STATIC = -1.0*FNL_STAT, NMO_STAT is the static that shifts
           traces to the final processing datum, and FNL_STAT is zero because
           your data are at the final datum.




Landmark                     ProMAX 3D Seismic Processing and Analysis          5-19
Chapter 5: Preprocessing and Elevation Statics




                                         Datum Statics Terminology


                              S.P.                       CDP

                                                                                Receiver


   N_DATUM
                                                                       NMO_STAT
       Surface
       Elevation
                   NMO_STAT

                                                FNL_STAT


                                     S_STATIC                  C_STATIC               R_STATIC


   F_DATUM




               Database Attributes:
                        N_DATUM = floating datum

                        F_DATUM = final datum

                        S_STATIC = (F_DATUM - ELEV + DEPTH) / DATUMVEL

                        R_STATIC = [(F_DATUM - ELEV + DEPTH) / DATUMVEL] - UPHOLE

                        C_STATIC = 2 * [(N_DATUM - F_DATUM) / DATUMVEL]


                   Trace Header Values:
                         N_DATUM = floating datum
                         NMO_STAT = S_STATIC + R_STATIC + C_STATIC
                        FNL_STAT = - C_STATIC
                        TOT_STAT = cumulative applied statics
                        NA_STAT = statics less than one sample period which are not-yet-applied

                                      (If TOT_STAT = 21.2 ms, and the sample period is 4 ms,
                                       NA_STAT = 1.2 ms)




5-20               ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                   Chapter 5: Preprocessing and Elevation Statics


      Comparison of Smoothed Surfaces based on CDP Smoothing
                    3D processing frequently requires you to compare the results of various
                    smoothing parameters on the floating datum surface. In the next
                    exercise we will calculate elevation statics using various settings for the
                    smoothing parameters and compare the surfaces using the Wire Frame
                    display in 3D XDB.


      Build and Execute a Flow to Compute the N-Datum
                    1. Build the following flow:

                   Editing Flow: 08- N_DATUM test

                   Add            Delete            Execute            View          Exit

                   Datum Statics Calculation
                         Elevation or Refraction----------------------------------Elevation
                         Final datum elevation-----------------------------------------1400
                         Replacement velocity -----------------------------------------9000
                         Database math method ------------------
                         --------------------------------------Shot Holes Using Uphole Info
                         NMO static method -------------------------------------Elevations
                         Length of smoother ------------------------------------------------51
                         Processing DATUM ---------------------------------NMO DATUM
                         Run ID-------------------------------------------------------------------01

                    2. In the Datum Statics Calculation module select Elevation, and
                       enter a final datum elevation of 1400 ft. with a replacement velocity
                       of 9000 ft/sec.

                         Since we are dealing with down hole data we will use the default
                         setting to incorporate the uphole data into the statics. We will select
                         Elevations for the NMO static method with a first guess of the using
                         the default setting of 51 CDP smoother. We will compute statics to
                         the NMO DATUM or floating datum for our processing datum. For
                         our first run leave the Run ID set to the default, 01.

                    3. After this flow completes generate two displays from the CDP
                       database using XDB Database Display (from DBTools select
                       Database ¦ XDB Database Display). When the XDB window




Landmark                               ProMAX 3D Seismic Processing and Analysis                5-21
Chapter 5: Preprocessing and Elevation Statics


                               appears, click 3D on the menubar and then your area, line, CDP,
                               X_COORD, Y_COORD, and either ELEV or N_DATUM.




                                   3D Wireframe: CDP: X_COORD, Y_COORD, ELEV


                                                                         51 point smoother




                                3D Wireframe: CDP: X_COORD, Y_COORD, N_DATUM




5-22           ProMAX 3D Seismic Processing and Analysis                               Landmark
                                           Chapter 5: Preprocessing and Elevation Statics


           4. Rerun the same flow but change the smoothing parameter to 15
              increment the Run ID to 02 and regenerate the wireframe plot of the
              new N_DATUM:

           Editing Flow: 08- N_DATUM test

           Add            Delete            Execute            View          Exit

           Datum Statics Calculation
                 Elevation or Refraction----------------------------------Elevation
                 Final datum elevation-----------------------------------------1400
                 Replacement velocity -----------------------------------------9000
                 Database math method ------------------
                 --------------------------------------Shot Holes Using Uphole Info
                 NMO static method -------------------------------------Elevations
                 Length of smoother ------------------------------------------------15
                 Processing DATUM ---------------------------------NMO DATUM
                 Run ID-------------------------------------------------------------------02

           .
                                                                  15 point smoother




                 3D Wireframe: CDP: X_COORD, Y_COORD, N_DATUM




Landmark                       ProMAX 3D Seismic Processing and Analysis                5-23
Chapter 5: Preprocessing and Elevation Statics


                           5. Compare these displays and decide on a value that does sufficient
                              smoothing without greatly changing the local elevation.

                             NOTE:

                             This project is very small with little elevation change. In normal production the
                             default smoother may be adequate. It is still worth looking at a the displays of ELEV
                             vs. N_DATUM after calculating the elevation statics for QC. This is especially true
                             in areas of highly variant surface elevations.



                           One major criterion that you might use to help diagnose a good value is
                           to look at the value of N_DATUM in the area of a proposed supergather
                           for velocity analysis. You would prefer that all CDPs in a supergather
                           have the same (or very similar) N_DATUM value.




5-24           ProMAX 3D Seismic Processing and Analysis                                                Landmark
                                                   Chapter 5: Preprocessing and Elevation Statics




Superswath Processing

                      The idea of splitting a data set into multiple parts and processing the
                      parts simultaneously has proven to be a valuable technique for
                      processing efficiently. A superswath is simply a subset of the entire
                      dataset after a particular processing step. Instead of processing the entire
                      data volume as one dataset, the volume is split up into several smaller,
                      more manageable datasets.




                    Swath 1                     ProMAX
                    Swath 2                     Process
                                                Flow
                    Swath 3
      Bundle the data sets into
      easy to manage
      partitions.

                     Swath 4                    ProMAX
                                                Process
                     Swath 5                    Flow
                     Swath 6

                                       Process each partition
                                       separately up to Stack
                                       or DMO Stack

                      The superswath strategy allow you to exploit the available hardware and
                      parallel processing techniques.




Landmark                                ProMAX 3D Seismic Processing and Analysis            5-25
Chapter 5: Preprocessing and Elevation Statics




Preprocessing Flows

                           The following exercise produces preprocessed, prestack data with
                           elevation statics applied.

                           In this set of exercises we will actually run two flows simultaneously.
                           The first flow will process the first half of the shots. The second flow
                           will be identical except that it will process the second half.

                           Since the elevation statics were already calculated in the database, we
                           only have to apply them to dataset trace headers using Datum Statics
                           Apply.


        Build a Flow to Perform the Preprocessing on the First Half
                           1. Build the flow outlined on the next page:

                           2. In Disk Data Input, input the first half shot file.

                           3. Select the mute you picked in Trace Mute.

                           4. Set True Amplitude Recovery parameters.

                               Apply spherical divergence using the time-velocity pairs given
                               below and a 6db/sec gain correction. Select No for velocity input
                               using a parameter table and enter the following time velocity pairs:

                               0-9700,500-11200,1200-12500,2000-14000

                           5. Set Spiking/Predictive Decon parameters.

                               You can use all of the default parameters except that you need to
                               input a previously picked miscellaneous time gate for the decon
                               design gate.

                           6. Bandpass Filter (Optional).

                               You can apply a bandpass filter in the decon process if desired.

                           7. In Datum Statics Apply select the source, receiver, and CDP statics
                              parameter corresponding to the Run ID with the best smoothed
                              surface.




5-26           ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                  Chapter 5: Preprocessing and Elevation Statics




                    Editing Flow: 09-Preprocessing 1st half

                    Add            Delete          Execute           View         Exit

                    Disk Data Input
                          Select dataset ---------------------- “shots - with geom (1st)”
                          Trace read option -------------------------------------------- Get All
                    Datum Statics Apply
                          Source datum statics ---------SIN GEOMETRY S_STAT02
                          Receiver datum statics------SRF GEOMETRY R_STAT02
                          CDP datum statics------------CDP CEOMETRY C_STAT02
                    True Amplitude Recovery
                          Apply spherical divergence corrections ------------------Yes
                          Basis for spherical spreading ---------------------------1/dist
                          Apply inelastic attenuation corrections --------------------No
                          Get TAR velocity function from db? -------------------------No
                          Specify TAR velocity function ----------------------------
                          --------------0-9000,500-11200,1200-12500,2000-14000
                          Apply dB/sec corrections?-------------------------------------Yes
                          dB/sec correction constant ---------------------------------------6
                          Maximum application TIME --------------------------------2000
                    Trace Muting
                          Select mute parameter file ---------------”first break mute”
                    Spiking/Predictive Decon
                          Use all defaults except...
                          Select decon gate parameter file --------------”decon gate”
                    Trace Display Label
                          Trace label -------------------------------decon and elev statics
                    Disk Data Output
                    Output Dataset -------------------------”shots- preprocessed (1st)”


      Label the Dataset and Output to Disk
                     8. Add Trace Display Label.

                          Use text similar to “decon and elev statics.”



Landmark                               ProMAX 3D Seismic Processing and Analysis            5-27
Chapter 5: Preprocessing and Elevation Statics


                           9. Set the Disk Data Output parameters.

                                Output a new file, describing the volume as shot organized with
                                decon and elevation statics applied for the first half of the data
                                volume such as “shots - preprocessed (1st)”

                           10. Execute the flow.


        Build a Flow to Perform the Preprocessing on the Second Half
                           1. Copy the flow that you just built to a new flow:


                          Editing Flow: 10-Preprocessing 2nd half

                          Add             Delete            Execute             View          Exit

                          Disk Data Input
                                Select dataset --------------------- “shots - with geom (2nd)”
                                Trace read option -------------------------------------------- Get All
                          Datum Statics Apply
                          True Amplitude Recovery
                          Trace Mute
                          Spiking/Predictive Decon
                          Trace Display Label
                          Disk Data Output
                                Output Dataset ------------------”shots-preprocessed (2nd)”

                           2. Change the input to your file for the second half.

                           3. Add a new output file for the preprocessed second half data.

                           4. Execute the flow.

                             NOTE:

                             Using this technique you can execute these two flows simultaneously on the same,
                             or different machines.




5-28           ProMAX 3D Seismic Processing and Analysis                                           Landmark
                                                                              Chapter 6
        3D Stack and Volume Comparison
In this chapter you will stack the data and then run a trace mix on the output volume to generate a
new volume. You will then build flows to display inline and crossline sections and time slices
from the stack volume. Finally, you will build a flow to compare stack volumes.

These flows will then be used later in the class whenever a new stack volume is generated.




Topics covered in this chapter:

                          t 3D RMS Velocity Field ASCII Import
                          t 3D Parameter Table Interpolation
                          t Picking a Post-NMO Mute
                          t Stack 3D
                          t Merging the Partial Stacks
                          t CDP/Ensemble Stack
                          t 3D Stack Volume Displays
                          t ProMAX 3D Viewer
                          t 3D Mix
                          t 3D Volume Comparisons




Landmark                                     ProMAX 3D Seismic Processing and Analysis          6-1
Chapter 6: 3D Stack and Volume Comparison




3D RMS Velocity Field ASCII Import

                         One critical part of the initial stack sequence is to apply normal
                         moveout. You may want to build a stacking (RMS) velocity parameter
                         table from a pre-existing field. The following exercise allows you to
                         import an ASCII RMS velocity field for making a parameter table.

                         1. From the list of flows level of the User Interface select the Tables
                            global option and then select to go to the list of VEL (RMS
                            (stacking) Velocity) tables.




                         2. Click Create. Do not click Add.




                         3. Enter the description name for your imported velocity. Use a name
                            similar to “imported from ascii file.”

                             This opens a parameter table editing window in the form of a
                             spreadsheet.

                         4. Select File ¦ Import.




6-2           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                        Chapter 6: 3D Stack and Volume Comparison


              This opens two more windows, an empty viewing window and a file
              selection window.




           5. Input the absolute path name to the directory where the velocity file
              is stored and append a /* to the end of the path (/misc_files/3d/*).
              Click Filter.

              This lists the files and directories stored in the specified directory.

           6. Select the file as indicated by your instructor and click OK.

              This opens the file and shows the contents in the Import viewing
              window.




           7. Click Format.




Landmark                    ProMAX 3D Seismic Processing and Analysis            6-3
Chapter 6: 3D Stack and Volume Comparison


                             This will open another window.




                         8. Enter a new format definition name or select a previously defined
                            format (you probably do not have one yet).

                         9. Click OK.

                             Another window will open listing CDP, X Coor, Y Coor, Inline,
                             Xline, TIME and VEL_RMS.




                         10. Click CDP and then drag the mouse over the appropriate columns
                             on the import file window to define the columns containing the
                             CDP value.




6-4           ProMAX 3D Seismic Processing and Analysis                             Landmark
                                         Chapter 6: 3D Stack and Volume Comparison


           11. Continue to define column numbers for TIME and VEL_RMS.




           12. Click Apply.

              This will open another window.




           13. Select Overwrite ALL existing values with new import values
               and click OK.




Landmark                      ProMAX 3D Seismic Processing and Analysis       6-5
Chapter 6: 3D Stack and Volume Comparison


                             This will load the values into the table.




                          NOTE:

                          The input file contains velocity functions using the 3D CDP number as reference.
                          ProMAX 3D requires that all parameter tables be referenced to X and Y
                          coordinates.



                         14. Use the Edit ¦ Resolve pull down menu to compute the X and Y
                             coordinates for each 3D CDP number.

                         15. Select Coordinates from the CDP ensemble numbers.

                         16. Use the Edit ¦ Resolve pull down menu to compute the Inline and
                             Crossline values for each 3D CDP number.




6-6           ProMAX 3D Seismic Processing and Analysis                                         Landmark
                                        Chapter 6: 3D Stack and Volume Comparison


              Select Inlines and xlines from coordinates.




              All columns should now be complete. This input table shows
              velocity functions on Xlines 20, 40 and 60 on Inlines 5, 15, 25 and
              35 for a total of 12 velocity functions set on a regular grid.

           17. Click on File ¦ Exit to save the parameter table and exit the editor.

           18. Check the table by going back to the list of tables from the User
               Interface and select to edit the table

           19. Click Edit and then select the table name.




              Notice that the table does not contain the Inline and Cross line values
              that we resolved for it. This is normal behavior. The Inline and
              Crossline numbers are not stored with the table.

           20. Select File ¦ Abort to exit the parameter table editor.




Landmark                     ProMAX 3D Seismic Processing and Analysis             6-7
Chapter 6: 3D Stack and Volume Comparison




3D Parameter Table Interpolation

                           In ProMAX 3D all parameter table interpolation is performed using the
                           X and Y coordinates. This applies to Velocities, Mutes, Horizons and
                           other types of parameter tables.




                                    2D Velocity Parameter Table

                                            CDP      Time      Vel

                                            1001          0    5000
                                                    1000       7000
                                                    2000      10000




                                    3D Velocity Parameter Table

                    CDP        Time      Vel          X        Y         Iline     Xline
                    1001        0      5000        10000      10000         1         1
                            1000       7000
                            2000      10000




                                          ProMAX 2D vs. 3D Parameter Tables




6-8           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                         Chapter 6: 3D Stack and Volume Comparison


           Interpolating velocity tables is a two step operation. A value at each of
           three velocity nodes is found at the desired time and then the velocity is
           interpolated using the Delauney Triangle approach.




            y                x

                     t
                                                 b

                            a               p
                                                                    c




                   Known x,y, v, t point
                    Interpolated x,y, v, t point


                             3D Parameter Table Interpolation
                                 Velocity Functions in 3D




Landmark                     ProMAX 3D Seismic Processing and Analysis            6-9
Chapter 6: 3D Stack and Volume Comparison




Picking a Post NMO Mute

                         The following exercise demonstrates a method to combine multiple
                         CDP gathers into a single ensemble in order to increase fold and offset
                         distribution. The resulting ensemble can then be used to pick a post
                         normal moveout mute.

                         1. Build the following flow:

                        Editing Flow: 11 - Pick post-NMO mute

                        Add            Delete          Execute           View         Exit

                        Disk Data Input
                              Select dataset ----------------------shots - preprocessed (1st)
                              Trace read option ------------------------------------------------Sort
                              Primary trace header entry ----------------CDP bin number
                              Interactive Data Access-------------------------------------------No
                              Secondary trace header entry -------------------------- NONE
                              Sort order for dataset ----------------------------------- 1615[7]/
                        Disk Data Insert
                              Insertion mode------------------------------------------------Merged
                              Select dataset --------------------shots - preprocessed (2nd)
                              Trace read option ------------------------------------------------Sort
                              Primary trace header entry ----------------CDP bin number
                              Secondary trace header entry -------------------------- NONE
                              Sort order for dataset ----------------------------------- 1615[7]/
                        Inline Sort
                              PRIMARY sort key -----------------------------CDP bin number
                              SECONDARY sort key -----Signed source-receiver offset
                              Maximum traces per output ensemble----------------------30
                        Ensemble Stack/Combine
                        Normal Moveout Correction
                        Bandpass Filter
                        Automatic Gain Control
                        Trace Display




6-10          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                           Chapter 6: 3D Stack and Volume Comparison




           Editing Flow: 11 - Pick post-NMO mute (cont)

           Add            Delete           Execute           View         Exit

           Disk Data Input
           Disk Data Insert
           Inline Sort
           Ensemble Stack/Combine
                 Type of operation --------------------------------- Combine Only
                 Input ensembles per output ensemble -----------------------7
                 Maximum traces per output ensemble -------------------200
                 Warnings if max traces/ens exceeded?------------------Yes
                 Primary Trace Order Header Word -------------------- (CDP)
                 ---------------------------------------------------------CDP bin number
                 Average the primary key values?-------------------------- Yes
                 Average the X and Y coord. of the primary key--------Yes
                 SECONDARY Trace Order Header Word--------(OFFSET)
                 -------------------------------------- Signed source-receiver offset
                 Output trace secondary key order -------------- Ascending
           Normal Moveout Correction
                 Direction for NMO application -------------------- FORWARD
                 Stretch mute percentage ----------------------------------------0.0
                 Apply any remaining static during NMO ---------------- Yes
                 Get 3D dip velocities? ---------------------------------------------No
                 Apply partial NMO?------------------------------------------------No
                 Get velocities from the database?---------------------------Yes
                 SELECT Velocity parameter file ----- imported from ascii
           Bandpass Filter
                 All default values are acceptable
           Automatic Gain Control
                 All default values are acceptable
           Trace Display
                 Primary trace LABELING ------------------------------------ CDP
                 Secondary trace LABELING --------------------------- OFFSET




Landmark                       ProMAX 3D Seismic Processing and Analysis            6-11
Chapter 6: 3D Stack and Volume Comparison


                         1. In the Disk Data Input, input the first half shot organized file that you
                            created with TAR and Decon applied.

                             Select to only read 7 CDPs starting at 3D CDP number 1615.

                         2. In the Disk Data Insert, input the second half shot organized file
                            that you created with TAR and Decon applied.

                             Select to only read 7 CDPs starting at 3D CDP number 1615.

                             You can make a display from the Database to help select the CDP
                             numbers. Make a 3D: XYGRAPH: CDP: ILN,XLN,FOLD display
                             and then convert the inline, crossline coordinates to CDP numbers.
                             In this case the equation would be (IL-1)*79+XLN.

                         3. Use the Inline Sort process to rebuild continuous CDP ensembles
                            since the selected CDPs are in the overlap zone between the two
                            files.

                         4. Use Ensemble Stack/Combine to build one ensemble of all the
                            input traces.

                             Select to join the 7 CDP ensembles into one ensemble and order the
                             traces by OFFSET. Specify a high number of traces per output
                             ensemble (200). Remember to average the CDP numbers and X, Y
                             coordinates.

                         5. Apply NMO using your best velocities available.

                             Remember to set the stretch mute to 0.0, disabling it.

                         6. Apply a Bandpass Filter and AGC for data enhancement.

                             The default parameters will be adequate.

                         7. Display the single ensemble.

                         8. Pick a top mute to remove any unwanted data interpolating the
                            times as a function of AOFFSET.




6-12          ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                       Chapter 6: 3D Stack and Volume Comparison


           9. Using the Picking ¦ Pick Top Mute... pull down menu input a
              new mute table name such as Post-NMO mute (brute) and click
              OK.




           10. Select to interpolate the time picks as a function of AOFFSET.

           11. Pick the mute.


Landmark                    ProMAX 3D Seismic Processing and Analysis       6-13
Chapter 6: 3D Stack and Volume Comparison


                             Be careful not to get to close to zero offset at time zero. Normally,
                             you will need to keep the near traces intact for the stack of the
                             shallow section.




                         12. Select File ¦ Exit/Stop Flow to save the table, exit, and stop the
                             flow.




6-14          ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                         Chapter 6: 3D Stack and Volume Comparison




Stack 3D

           Sorting data for a large 3D volume can be time consuming and
           expensive. ProMAX 3D offers the capability to generate “partial CDP
           stacks” from input files of any primary ensemble and merge these partial
           stacks together into one final CDP stack data volume. Of course, if all
           traces are input to a single Stack 3D execution, no merging is necessary.

           In the following exercises we will create two separate partial stacks and
           merge them together.



                             42                   16


                                                                      first half
                                                                      input data
                 second
                 half
                 input data




                                           26                     1


                           Stack 3D Overlapping Partial Stacks




Landmark                     ProMAX 3D Seismic Processing and Analysis             6-15
Chapter 6: 3D Stack and Volume Comparison


       Run Stack3D on the First Superswath
                         1. Build the following flow:


                        Editing Flow: 12- stack - initial (1st)

                        Add            Delete           Execute            View          Exit

                        Disk Data Input
                              Select dataset ---------------------shots - pre processed (1st)
                              Trace read option -------------------------------------------- Get All
                        Normal Moveout Correction
                              Direction for NMO application -------------------- FORWARD
                              Stretch mute percentage ----------------------------------------- 0.
                              Long offset correction----------------------------------------------No
                              Anisotropy correction parameter eta-----------------------0.0
                              Apply partial NMO?------------------------------------------------No
                              SELECT Velocity parameter file ----- Imported from ascii
                        Trace Muting
                              SELECT mute parameter file ---- Post-NMO mute (brute)
                        Stack 3D
                              Enter name of host -----------------------------
                              Number of worker threads----------------------------------------1
                              Restart with an existing stack? ------------------------------No
                              Minimum inline number -------------------------------------------1
                              Maximum inline number -----------------------------------------26
                              Minimum crossline number---------------------------------------1
                              Maximum crossline number ------------------------------------79
                              Exponent of normalization factor -------------------------- 0.5
                              Number of normalization scalars per trace ----------- 100
                              Apply final datum statics after stack? -------------------yes
                              Size of input trace memory buffer (MB)---------------------- 4
                              Size of stack trace memory buffer (MB) ----------------------4
                        Trace Display Label
                              Trace label-------------------------------------------------Initial (1st)
                        Disk Data Output
                              Output dataset filename--------------------stack-initial (1st)

                         2. In Disk Data Input, input the first half of the shot-organized file


6-16          ProMAX 3D Seismic Processing and Analysis                                       Landmark
                                         Chapter 6: 3D Stack and Volume Comparison


              with decon and applied elevation statics applied.

           3. Before selecting the file, click MB2 on the filename and look at the
              minimum and maximum CDP that this file contributes to. We will
              use this to set the parameters for Stack 3D.




                                              4
                                              2036




              This file contributes to CDP’s 4 - 2036 This translates to Inlines 1 -
              26.

              SelctGet All.

           4. In the Normal Moveout select the velocity table that we built
              previously and set the stretch mute to 0.0 percent thus disabling it.

           5. Apply the post-NMO mute picked previously in the Trace Muting
              flow.

              In Stack 3D, enter the minimum and maximum lines contributing to
              the input dataset.

              In this case the second file contributes to lines 1 through 26.

           6. Since there will be several jobs running simultaneously we will
              need to reduce the memory usage for each job. Set the memory to 4
              MB for both the input and output buffers.

           7. In Trace Display Label, label this as the initial stack on the first half
              of the project.

           8. In Disk Data Output, output a stack with decon and elevation statics
              from Stack 3D.




Landmark                      ProMAX 3D Seismic Processing and Analysis          6-17
Chapter 6: 3D Stack and Volume Comparison


                         9. Execute the flow.


       Run Stack3D on the Other Superswath
                         1. Copy the flow for the first half stack to a new flow for the second
                            half:

                        Editing Flow: 13- stack - initial (2nd)

                        Add            Delete           Execute            View         Exit

                        Disk Data Input
                              Select dataset --------------------shots - pre processed (2nd)
                              Trace read option -------------------------------------------- Get All
                        Normal Moveout Correction
                        Trace Muting
                        Stack 3D
                              Minimum inline number -----------------------------------------16
                              Maximum inline number -----------------------------------------42
                              Minimum crossline number---------------------------------------1
                              Maximum crossline number ------------------------------------79
                        Trace Display Label
                              Trace label -----------------------------------------------initial (2nd)
                        Disk Data Output
                              Output Dataset Filename----------------stack - initial (2nd)

                         2. Change the Disk Data Input filename to shot-organized file for the
                            second half of the project.

                         3. In Stack 3D, enter the minimum and maximum lines contributing to
                            the input dataset.

                              In this case the second file contributes to lines 16 through 42.

                         4. In Disk Data Output, set the filename to be an initial stack file for
                            the second half of the project.

                         5. Execute the flow.




6-18          ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                           Chapter 6: 3D Stack and Volume Comparison




Merging the Partial Stacks

             In this exercise, we will execute a flow to stack merge the two “partial
             stack” files into one stack for the entire project.

             1. Build the flow as outlined on the next page.

             2. In Disk Data Input, input the first half partial stack file.

             3. In the Disk Data Insert, input the second half partial stack file.

             4. In the Stack Merge 3D, set the normalization exponent and number
                of normalization scalars so they are the same as those used in the
                Stack 3D flows (0.5 and 100).

                Set the minimum line number to 1 and the maximum to 42. This
                represents the entire project.

             5. Set the input and output memory buffers to 4 MB again since we
                will be running several jobs simultaneously.

             6. Add a Trace Display Label such as “stack-initial
                (merged)”.

             7. Output the dataset to disk.




Landmark                       ProMAX 3D Seismic Processing and Analysis            6-19
Chapter 6: 3D Stack and Volume Comparison


                         8. Execute the flow.


                        Editing Flow: 14- merge 3d stacks

                        Add            Delete           Execute           View         Exit

                        Disk Data Input
                              Select dataset -------------------------------- stack - initial (1st)
                              Trace read option -------------------------------------------- Get All
                        Disk Data Insert
                              Insertion Mode -------------------------------------------------- After
                              Select dataset ------------------------------- stack - initial (2nd)
                              Trace read option -------------------------------------------- Get All
                        Stack Merge 3D
                              Enter name of host -----------------------------
                              Restart with an existing stack? ------------------------------No
                              Minimum inline number -------------------------------------------1
                              Maximum inline number -----------------------------------------42
                              Minimum crossline number---------------------------------------1
                              Maximum crossline number ------------------------------------79
                              Exponent of normalization factor -------------------------- 0.5
                              Number of normalization scalars per trace ----------- 100
                              Size of input trace memory buffer (MB)-----------------------4
                              Size of stack trace memory buffer (MB) ----------------------4
                        Trace Display Label
                              Trace label ----------------------------------------- initial (merged)
                        Disk Data Output
                              Output Dataset Filename-----------stack - initial (merged)




6-20          ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                    Chapter 6: 3D Stack and Volume Comparison


      Alternative Stack Merge Method ------ DO NOT BUILD THIS FLOW
                     Build the following flow as a comparison:


                    Editing Flow: 15- merge 3d append

                    Add            Delete           Execute           View         Exit

                    Disk Data Input
                          Select dataset ------------------------------- Stack - initial (2nd)
                          Trace read option -------------------------------------------- Get All
                    Stack Merge 3D
                          Restart with an existing stack? -----------------------------Yes
                          Select existing stack filename -----------Stack -initial (1st)
                          Subtract input from stack? -------------------------------------No
                          Minimum inline number -------------------------------------------1
                          Maximum inline number -----------------------------------------42
                          Minimum crossline number---------------------------------------1
                          Maximum crossline number ------------------------------------79
                    Trace Display Label
                    Disk Data Output

                     1. In Disk Data Input, input the second half partial stack file.

                     2. In the Stack 3D menu, choose Yes to Restart with an existing stack
                        and enter the first half partial stack file.

                          You can use this approach if the partial stack jobs do not all finish at
                          the same time. You can start merging the completed files and
                          continue merging as the files become available.

                          One requirement is that the file that is being added to within the
                          Stack Merge must have been built originally to encompass all of the
                          data that is going to be added to it. This is why it will not work for
                          our case. Our partial stack files were built to only contain CDPs that
                          were contributed to by the input data.


      The Subtraction option
                          This option in the Stack Merge is intended as a means by which you
                          can remove the effects of one (or more) bad trace(s) from an stack
                          volume. This is actually more appropriate for merging DMO to


Landmark                                ProMAX 3D Seismic Processing and Analysis           6-21
Chapter 6: 3D Stack and Volume Comparison


                             Stack 3D volumes where a few of bad traces have influenced many
                             output traces.

                             If bad traces are detected, the input process, Stack3D or DMO to
                             Stack 3D can be rerun with these traces only. The resulting partial
                             stack of the bad traces can then be subtracted from the total instead
                             of rerunning each stack and merge flows to eliminate the bad input
                             traces.




6-22          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                        Chapter 6: 3D Stack and Volume Comparison




3D Stack Volume Displays

                        In this exercise we will build flows to display inlines, crosslines, and
                        time slices from the stack volume.


      Inline Displays
                        The following exercise produces inline displays of the 3D stack volume.

                        1. Build the following flow:


                        Editing Flow: 16- Display Inlines

                        Add            Delete           Execute           View         Exit

                        Disk Data Input
                              Select dataset -------------------------- stack - initial (merged)
                              Trace read option ------------------------------------------------ Sort
                              Interactive Data Access ---------------------------------------- Yes
                              primary trace header ------( ILINE_NO) 3D inline number
                              secondary trace header ---------(XLINE_NO) 3D crossline
                              tertiary trace header -----------------------------------------NONE
                              Sort order for dataset --------------------------1,5-40(5),42:*/
                        Bandpass Filter
                              The default parameters will be adequate
                        Automatic Gain Control
                              The default parameters will be adequate
                        Trace Display
                              Number of ENSEMBLES / screen ----------------------------10
                              Primary trace LABELING --------(ILINE_NO) 3D inline no.
                              Secondary trace LABELING ---(XLINE_NO) 3D crossline

                        2. In Disk Data Input, input the initial stack (after merge) data volume.

                              Sort the input with a primary sort of inline and secondary of
                              crossline. Set the sort order to 1, 5-40(5), 42: */

                        3. Apply a Bandpass Filter and AGC to make the stack look better.



Landmark                                    ProMAX 3D Seismic Processing and Analysis            6-23
Chapter 6: 3D Stack and Volume Comparison


                         4. Set the Trace Display parameters.

                              Select to plot 10 ensembles and set the primary and secondary
                              annotations as ILINE_NO and XLINE_NO. This will plot too
                              many traces per screen on the first plot but Trace Display allows you
                              to zoom and scroll.

                         5. Execute the flow.


       Crossline Displays
                         The following exercise produces crossline displays of the 3D stack
                         volume.

                         1. Build the following flow:

                              This flow is very similar to the Display inlines flow that you just
                              built. You may want to copy that flow to save some work.

                        Editing Flow: 17- Display crosslines

                        Add            Delete           Execute           View         Exit

                        Disk Data Input
                              Select dataset ------------------------- Stack - initial (merged)
                              Trace read option ------------------------------------------------ Sort
                              Interactive Data Access ---------------------------------------- Yes
                              primary trace header -------( XLINE_NO) 3D crossline no
                              secondary trace header ----(ILINE_NO) 3D inline numbe
                              tertiary trace header -----------------------------------------NONE
                              Sort order for dataset ----------------------1,10-70(10),79:*/
                        Bandpass Filter
                              The default parameters will be adequate
                        Automatic Gain Control
                              The default parameters will be adequate
                        Trace Display
                              Number of ENSEMBLES / screen ----------------------------10
                              Primary trace LABELING -------(XLINE_NO) 3D crossline
                              Secondary trace LABELING -----(ILINE_NO) 3D inline no

                         2. In Disk Data Input, input the initial stack (after merge) data volume.


6-24          ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                       Chapter 6: 3D Stack and Volume Comparison


              Sort the input with a primary sort of crossline and secondary of
              inline. Select to plot crosslines and inlines as follows:

              1, 10-70(10), 79: */

           3. Apply a Bandpass Filter and AGC to make the stack look better.

           4. Set the Trace Display parameters.

              Select to plot 9 ensembles and set the primary and secondary
              annotations as XLINE_NO and ILINE_NO. This will plot too
              many traces per screen on the first plot but Trace Display allows you
              to zoom and scroll.

           5. Execute the flow.




Landmark                    ProMAX 3D Seismic Processing and Analysis         6-25
Chapter 6: 3D Stack and Volume Comparison


       Time Slice Displays
                              The following exercise produces time slice displays of the 3D stack
                              volume.

                         1. Build the following flow:


                        Editing Flow: 18- Display time slices

                        Add            Delete          Execute           View         Exit

                        Time Slice Input
                              Select dataset ---------------------------stack - initial (merged)
                              Type of time slice --------------------------------- Constant time
                              List of times ---------------------------------------- 200-1700(100)
                              Number of samples to stack -------------------------------------1
                              Store results in CDP database? ----------------------------- No
                              Horizontal axis ------------------------------ INLINE (ILINE_NO)
                              Horizontal axis increment --------------------- DECREASING
                              Vertical axis increment ------------------------- DECREASING
                        Trace Display Label
                              Trace label ----------------------------------------- initial (merged)
                        Trace Display
                              number of ENSEMBLES/screen ----------------------------- 16
                              Trace gap between ensembles----------------------------------3
                              Trace display MODE----------------------------------- Grayscale
                              Primary trace LABELING ---------- slc_time (user defined)
                              Secondary trace LABELING -----(ILINE_NO) 3D inline no

                         2. Set Time Slice Input parameters.




6-26          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                         Chapter 6: 3D Stack and Volume Comparison


              Select to plot time slices every 100 ms between 200 and 1700 msec.
              This will produce 16 time slices.

                                    42        Inline Number
                                                                         1
                                79




                         Crossline
                         Number




                                1
                                                  horizontal



                              Time Slice Display Orientation

              To match the display and a map view of this project, set the
              Horizontal axis to be Inlines Decreasing to the right and set the
              Vertical axis to Decrease, thus plotting Xline 79 on the top and inline
              1 on the right.

           3. Select the Trace Display parameters.

              Select 16 for ensembles to plot and set the Primary Annotation to
              slc_time (a user defined header) and the secondary annotation to
              ILINE_NO. You may also find that using a Grayscale mode makes
              the display more visually appealing. Adding a larger gap between
              ensembles will also help visually separate the time slices.

Landmark                    ProMAX 3D Seismic Processing and Analysis           6-27
Chapter 6: 3D Stack and Volume Comparison




ProMAX 3D Viewer

                         The ProMAX 3D Viewer is a 3D data volume visualization tool. IT will
                         allow you to view a post stack 3D data volume rendered in 3D space
                         where Inlines, Crosslines and time slices can be viewed simultaneously.
                         Box, or cube displays can also be generated.

                         The ProMAX 3D Viewer can display seismic trace data and/or 3D
                         velocity tables. Horizons, faults, and other interpretive entities cannot be
                         viewed using the viewer, but they can be viewed given a full
                         OpenVision license and access to the OpenWorks Oracle database.

                         In this section you will learn how to start the viewer and add different
                         components to the display.

                         1. Build and execute the following flow:

                        Editing Flow: 19- 3D Viewer

                        Add            Delete          Execute           View         Exit

                        ProMAX 3D Viewer*

                         There are no parameters that need to be set for this standalone process.

                         The program may promt you as to which monitor to display the viewer
                         on and a second prompt will want to know where to display the data
                         selection dialog boxes. By default the program will start on the higher
                         level graphic screen and you may only get one screen selection




6-28          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                         Chapter 6: 3D Stack and Volume Comparison


           opportunity. When the intialization is complete you should get a display
           similar to the following example:




           2. Use the Data ¦ ProMAX pulldown menu to access seismic data
              and/or velocity cube data. Lets start with the Seismic Animator

              A Dialog box will appear asking you to choose a dataset to display
              and then several parameters about how to slice the cube. First, let’s
              select the merged initial stack file. The remaining parameters
              suggest displaying all traces. You may want to decimate the stack
              volume to display a subset of the lines but all traces on each line. For
              this first example just let the remaining parameters default and click
              on the APPLY button. One line should appear on the display. Repeat
              the process, but select to do a TRACE oriented display and then a
              time slice oriented display.




Landmark                    ProMAX 3D Seismic Processing and Analysis            6-29
Chapter 6: 3D Stack and Volume Comparison




  Select Line,
  Trace and TimeSlice
  here




                         Basic available functionality includes the ability to rotate the image by
                         holding down MB2 and moving the mouse, changing the vertical
                         scaling, and display zoom capabilities.


                                                                                Zoom


                      options/                                                 Vertical Scaling
                      user preferences




                                                                               Select Rotation
                                                                               vs. Translation




6-30          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                        Chapter 6: 3D Stack and Volume Comparison


              Some screen customization can also be performed by the various
              dialog boxes under the Options pull down menu.

           3. Click on one of the entities on the display. You can move from one
              Line, Crossline, or Timeslice to another by holding down MB1 and
              dragging the cursor up and down in the screen.

              The green directional buttons at the bottom of the screen can also be
              used to move through the available data.

           4. Add a Velocity model to the display by choosing the Data ¦
              ProMAX ¦ Velocity Animator pull down option. Select the
              velocity file that you inported from the ASCII file earlier. Choose
              the BOX option and use the Rainbow color scheme with a 50 %
              transparency setting.




           5. You can move the BOX edges by clicking on the side of the box and
              moving the cursor up and down the screen while holding down
              MB1.

           6. Ask your instructor for more information as you play with the other
              options and buttons.




Landmark                    ProMAX 3D Seismic Processing and Analysis          6-31
Chapter 6: 3D Stack and Volume Comparison




3D Mix

                         The following exercise applies a running mix to the initial stack in order
                         to produce an additional stack volume that looks different from the
                         input. These two stack volumes will then be used to demonstrate the
                         stack volume comparison procedure.


       Apply a 3D Running Mix to the Initial Stack
                         1. Build the following flow:

                         This flow is very similar to the “Merge 3D stacks” flow. You may want
                         to copy that flow to save some work.

                        Editing Flow: 20- 3D mix on initial stack

                        Add            Delete          Execute           View         Exit

                        3D Mix
                              Select dataset ---------------------- stack - initial (merged)
                              IN-LINE the X-LINE sort order--------------------------- *:*/
                              Trace mixing algorithm --------------------- Weighted Mix
                              Exclude ‘hard’ zeros?------------------------------------- Yes
                              Trace weights for mixing ---------------------- 1.0,1.0,1.0
                              Number of traces to mix over------------------------------- 3
                              Type of trace edge taper ------------------ Fold edge back
                              Application mode for mixed traces--------------- Normal
                              Steer trace mix along a velocity dip?------------------ No
                              Number of applications ------------------------------------- 1
                              Re-apply mutes after mixing --------------------------- Yes
                        Trace Display Label
                              Trace label ------------------------------------ initial (3dmix)
                        Disk Data Output
                              Output Dataset Filename---------stack - initial (3dmix)




6-32          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                  Chapter 6: 3D Stack and Volume Comparison


                     2. In 3D Mix, input the stack with elevation statics applied.

                      NOTE:

                      3D Mix is an input process that automatically sorts with a primary key
                      of ILINE_NO and secondary key of XLINE_NO. Do not use Disk
                      Data Input.


                        Select to process all inlines and all xlines (*:*/). Change the number
                        of trace weights to 3 and use the weight values (1.0,1.0,1.0).

                     3. In Trace Display Label, label as “initial (3dmix)”.

                     4. In Disk Data Output, output a stack with 3D Mix file.

                     5. Execute the flow.


      Display the Mixed Stack
                     You have already build a flow to display some inlines, crosslines and/or
                     time slices from this volume.

                     1. Reselect your Display Inlines flow.

                        Change the input filename and execute the flow.

                     2. Display some crosslines and time slices.




Landmark                              ProMAX 3D Seismic Processing and Analysis          6-33
Chapter 6: 3D Stack and Volume Comparison




3D Stack Volume Comparison Preparation

                         Eventually we are going to have multiple stack volumes of the same
                         project and we are going to want to compare one volume vs. another. For
                         example, we are preparing to generate an “Initial Stack”. We will then
                         generate a stack after refraction statics and then another stack after
                         residual statics followed by another stack after velocity analysis and so
                         on. After each processing stage we will be interested in the progress of
                         the stack to make sure that the stack response and lateral continuity are
                         improving after each processing stage.

                         For a 3D volume you will normally not compare every inline or
                         crossline; instead you will want to select a subset for QC. The problem
                         is that each stack data volume is essentially identical except for the
                         amplitudes and the label header word. Each volume has the same CDP
                         numbers and the same inline and crossline numbers. In order to compare
                         a subset of lines or crosslines efficiently we will need to sort on a
                         characteristic that varies between the two (or more) stack volumes.

                         The diagram on the next page shows the basic strategy involved in
                         preparing 3D stack data volumes for comparison. When you read
                         multiple datasets within a flow ProMAX generates a header word for the
                         dataset sequence number called DS_SEQNO. The first dataset read will
                         have DS_SEQNO equal to one and in subsequent datasets DS_SEQNO
                         will increment.

                         Using DS_SEQNO will allow us to read the same inline (or crossline)
                         from multiple stack data volumes and align them in the processing flow
                         so that they are presented to the screen in a specific order. We want the
                         same ILINE_NO from the two volumes to be adjacent in the processing
                         flow so that they can be displayed on the screen simultaneously or can
                         be displayed one after the next for screen swapping comparison.




6-34          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                   Chapter 6: 3D Stack and Volume Comparison




                   DS_SEQNO                                        DS_SEQNO
                     1                                                2




           1 10 30 42               ILINE_NO              1 10 30 42

 DDI and DDInsert (Merge) read inlines of interest from each volume

 ILINE_NO          1      1        10      10          30     30            42      42




 DS_SEQNO          1       2        1        2            1   2             1       2

 Inline Sort splits the ILINE_NO merged ensembles by input dataset
 sequence number, and then sorts by crossline

 ILINE_NO     1            1      10        10       30       30       42        42




 DS_SEQNO      1           2       1        2         1        2        1           2


                       Stack Volume Display Comparison Strategy



Landmark                                ProMAX 3D Seismic Processing and Analysis        6-35
Chapter 6: 3D Stack and Volume Comparison




3D Stack Comparisons

                         These exercises produce the following three flows:

                         •   One compares inline stacks from different 3D volumes.

                         •   One compares crossline stacks from different 3D volumes.

                         •   One compares time slices from different 3d volumes.


       Compare Inlines from Two Stack Volumes
                         1. Build the flow as outlined on the next page.

                         2. In the Disk Data Input, input the initial stack after merge.

                             Sort using 3D inline as primary and 3D crossline as secondary.
                             Select inlines 1, 5-40(5) and 42 and all 3D crosslines (*).

                         3. In Disk Data Insert, read the initial stack and merge it with 3D mix
                            observing dataset boundaries but not forcing the datasets to merge.

                             Select Merged for Insert mode. Use the same primary and
                             secondary sort order as Disk Data Input and select the same 3D
                             inlines.

                         4. Select the Inline Sort parameters.

                             Select 3D inline number (ILINE_NO) for the primary sort key and
                             Input dataset sequence number (DS_SEQNO) from the alternate
                             list for the secondary sort key. Next, select 3D crossline number
                             (XLINE_NO) for the tertiary sort key. Change the maximum
                             number of traces in the ensemble to the maximum number of traces
                             you have per inline (79). This sorts the data so that the same inlines
                             from each volume are adjacent to each other for display. Finally,
                             select Secondary for the Sort key to control end-of-ensemble so
                             each inline appears as separate ensemble.

                         5. Select Filter and AGC parameters.

                             Use the default parameters.

                         6. In Trace Display, display all selected lines for comparison.


6-36          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                       Chapter 6: 3D Stack and Volume Comparison


              Select 20 ensembles per screen. Select ILINE and XLINE for the
              primary and secondary trace labeling header entries.

              After executing the flow, use the scrolling Zoom option to compare
              the lines.

           7. You may elect to display 1 ensemble per screen and the save the
              screens for comparison.




Landmark                    ProMAX 3D Seismic Processing and Analysis       6-37
Chapter 6: 3D Stack and Volume Comparison


                         8. This flow is an extension of the Display Inlines flow, built earlier.
                            You may want to copy that flow to save yourself some work.

                        Editing Flow: 21- Compare inlines

                        Add            Delete           Execute           View         Exit

                        Disk Data Input
                              Select dataset ------------------------- Stack - initial (merged)
                              Trace read option ------------------------------------------------ Sort
                              Interactive Data Access ------------------------------------------No
                              primary trace header ------( ILINE_NO) 3D inline number
                              secondary trace header ----(XLINE_NO) 3D crossline no
                              tertiary trace header -----------------------------------------NONE
                              Sort order for dataset --------------------------1,5-40(5),42:*/
                        Disk Data Insert
                              Insertion mode -----------------------------------------------Merged
                              Maximum traces per output ensemble -----------------------0
                              Select dataset --------------------------- Stack - initial (3dmix)
                              Trace read option ------------------------------------------------ Sort
                              primary trace header ------( ILINE_NO) 3D inline number
                              secondary trace header ----(XLINE_NO) 3D crossline no
                              tertiary trace header -----------------------------------------NONE
                              Sort order for dataset --------------------------1,5-40(5),42:*/
                              Force datasets to merge -----------------------------------------No
                              Observe dataset boundaries ---------------------------------Yes
                        Inline Sort
                              PRIMARY sort key ---------- (ILINE_NO) 3D inline number
                              SECONDARY sort---------------(DS_SEQNO) Input dataset
                                      sequence number
                              TERTIARY sort key----(XLINE_NO) 3D crossline number
                              Maximum traces per output ensemble -------------------- 79
                              Number of traces in buffer ------------------------------------160
                              Buffer type ----------------------------------------------------Memory
                              Sort key which controls End-of-Ensemble-----Secondary
                        Bandpass Filter
                        Automatic Gain Control
                        Trace Display


6-38          ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                  Chapter 6: 3D Stack and Volume Comparison




                   Editing Flow: 21- Compare inlines

                   Add            Delete          Execute          View        Exit

                   Disk Data Input
                   Disk Data Insert
                   Inline Sort
                   Bandpass Filter
                         The default parameters will be adequate
                   Automatic Gain Control
                         The default parameters will be adequate
                   Trace Display
                         Number of ENSEMBLES / screen ----------------------------20
                         Primary trace LABELING ---------(ILINE_NO) 3D inline no
                         Secondary trace LABELING ---(XLINE_NO) 3D crossline
                   >Trace Display<
                         Number of ENSEMBLES / screen ------------------------------1


      Compare Crosslines from Two Stack Volumes
                    1. Build the flow as outlined on the next page.

                    2. In Disk Data Input, input the Stack with elevation statics.

                         Sort using 3D xline as primary and 3D inline as secondary. Select
                         crosslines 1, 10-70(10) and 79 and all 3D inlines (*).

                    3. In Disk Data Insert, read the Mix Stack.

                         Select After for Insert mode. Use the same primary and secondary
                         sort order as Disk Data Input and select the same 3D xlines.

                    4. Select Inline Sort parameters.

                         Select 3D crossline number (XLINE_NO) for the primary sort key
                         and Input dataset sequence number (DS_SEQNO) from the
                         alternate list for the secondary sort key. Next, select 3D inline
                         number (ILINE_NO) for the tertiary sort key. Change the
                         maximum number of traces in the ensemble to the maximum
                         number of traces you have per crossline (42). This sorts the data so


Landmark                               ProMAX 3D Seismic Processing and Analysis         6-39
Chapter 6: 3D Stack and Volume Comparison


                             that the same crosslines from each volume are adjacent to each other
                             for display. Finally, select Secondary for the Sort key to control end-
                             of-ensemble so each crossline appears as separate ensemble.

                         5. Select Filter and AGC parameters.

                             Use the default parameters.

                         6. In Trace Display, display all selected crosslines for comparison.

                             Select 18 ensembles per screen. Select XLINE and ILINE for the
                             primary and secondary trace labeling header entries.

                             After executing the flow, use the scrolling Zoom option to compare
                             the lines.

                         7. You may elect to display 1 ensemble per screen and the save the
                            screens for comparison.




6-40          ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                           Chapter 6: 3D Stack and Volume Comparison


           This flow is an extension of the Display Crosslines flow, built earlier.
           You may want to copy that flow to save yourself some work.

           Editing Flow: 22- Compare Cross lines

           Add            Delete           Execute           View         Exit

           Disk Data Input
                 Select dataset ------------------------- Stack - initial (merged)
                 Trace read option ------------------------------------------------ Sort
                 primary trace header -------( XLINE_NO) 3D crossline no
                 secondary trace header ---(ILINE_NO) 3D inline number
                 tertiary trace header -----------------------------------------NONE
                 Sort order for dataset ----------------------1,10-70(10),79:*/
           Disk Data Insert
                 Insertion mode -----------------------------------------------Merged
                 Maximum traces per output ensemble -----------------------0
                 Select dataset --------------------------- Stack - initial (3dmix)
                 Trace read option ------------------------------------------------ Sort
                 primary trace header ------( XLINE_NO) 3D crossline no.
                 secondary trace header ---(ILINE_NO) 3D inline number
                 tertiary trace header -----------------------------------------NONE
                 Sort order for dataset ----------------------1,10-70(10),79:*/
                 Force datasets to merge -----------------------------------------No
                 Observe dataset boundaries ---------------------------------Yes
           Inline Sort
           Bandpass Filter
           Automatic Gain Control
           Trace Display
           >Trace Display<




Landmark                       ProMAX 3D Seismic Processing and Analysis            6-41
Chapter 6: 3D Stack and Volume Comparison




                        Editing Flow: 22- Compare Cross lines (cont)

                        Add            Delete          Execute           View         Exit

                        Disk Data Input
                        Disk Data Insert
                        Inline Sort
                              PRIMARY sort key ---- (XLINE_NO) 3D crossline number
                              SECONDARY sort---------------(DS_SEQNO) Input dataset
                                      sequence number
                              TERTIARY sort key----------(ILINE_NO) 3D inline number
                              Maximum traces per output ensemble -------------------- 42
                              Number of traces in buffer --------------------------------------90
                              Buffer type ----------------------------------------------------Memory
                              Sort key which controls End-of-Ensemble-----Secondary
                        Bandpass Filter
                              The default parameters will be adequate
                        Automatic Gain Control
                              The default parameters will be adequate
                        Trace Display
                              Number of ENSEMBLES / screen ----------------------------18
                              Primary trace LABELING ------ (XLINE_NO) 3D crossline
                              Secondary trace LABELING ---------(ILINE_NO) 3D inline
                        >Trace Display<
                              Number of ENSEMBLES / screen ------------------------------1


       Compare Time Slices from Two Stack Volumes
                         1. Edit the Display Time Slices flow.

                         It is not as convenient to compare the time slices as with the inlines and
                         crosslines. The most effective way is to execute the same flow twice




6-42          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                           Chapter 6: 3D Stack and Volume Comparison


           with two different input files and then size the windows as appropriate
           to compare the two volumes.

           Editing Flow: 18- Display Time Slices

           Add            Delete           Execute           View         Exit

           Time Slice Input
                 Select dataset --------------------------------------------- select file
                 Type of time slice --------------------------------- Constant time
                 List of times ---------------------------------------- 200-1700(100)
                 Number of samples to stack -------------------------------------1
                 Store results in CDP database? ----------------------------- No
                 Horizontal axis ----------------------------- IN LINE (ILINE_NO)
                 Horizontal axis increment --------------------- DECREASING
                 Vertical axis increment ------------------------- DECREASING
           Trace Display Label
                 Trace label ------------------------ volume identifier label text
           Trace Display
                 number of ENSEMBLES/screen ----------------------------- 16
                 Trace gap between ensembles----------------------------------3
                 Trace display MODE---------------------------------- Grayscale
                 Primary trace LABELING ------------------------------- slc_time
                 Secondary trace LABELING -----(ILINE_NO) 3D inline no




Landmark                       ProMAX 3D Seismic Processing and Analysis            6-43
Chapter 6: 3D Stack and Volume Comparison




6-44          ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                                 Chapter 7
                  Neural Net First Break Picking
This section covers the steps for picking the first arrival time that are required as input into to
various processes such as Source Receiver Geom Check*, Trace Statistics and Refraction Statics.
We will use the neural network approach to picking first breaks.

Because the data quality of the first arrivals is poor on this dataset and the results are variable from
user to user, we will read in a set of good picks for future processing.




Topics covered in this chapter:

                           t Neural Network First Break Picking Overview
                           t Neural Network FB Training
                           t Neural Network First Break Picking
                           t Importing First Break Picks




Landmark                                       ProMAX 3D Seismic Processing and Analysis            7-1
Chapter 7: Neural Net First Break Picking




Neural Network First Break Picking Overview

                            Artificial neural networks have been proven to excel in solving pattern
                            recognition problems. First break picking, trace editing, and reversed
                            trace selection, typically tedious processing steps, are inherently pattern
                            recognition problems, thus lending themselves to the application of
                            neural networks.

                            For first break picking and trace editing, ProMAX uses a Cascade-
                            Correlation Learning Architecture. Advantages of this algorithm
                            include decreased network learning time and the ability to incrementally
                            add to an existing network. The neural network compares various
                            attributes of the correct pick to other possible picks within a window.
                            The network recognizes the ability of an attribute to predict the correct
                            pick, and accordingly weights the network connection to that attribute.

                            In order to run neural net training and picking, you must have completed
                            geometry and assigned valid trace numbers to your input dataset. Neural
                            network training and testing can be done interactively within Trace
                            Display. Using the trained network to pick all of the traces is done in
                            batch mode using the Neural Network First Break Picker process.

                            The neural network learns from you. It will attempt to pick first breaks
                            by trying to reproduce your results.




7-2             ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                               Chapter 7: Neural Net First Break Picking




Neural Network FB Training

             There is an interactive method of doing the neural network training and
             testing in Trace Display. The production neural net first break picking
             will generally be done in batch mode.

             Before running the neural net first break training, you must prepare the
             data by performing any necessary trace edits and reversals. You will
             then pick some first breaks from which the algorithm can learn and pick
             a miscellaneous time gate around the first breaks. The manual picks and
             time gate will be picked interactively within Trace Display.

             1. Build the flow as outlined on the next page.

             2. Select the file that we wrote to disk that contains the 5 test shots.

                When we picked the parameter tables we decided on 4 shots that
                were located at the corners of the project and 1 shot in the middle.
                These shots should be adequate for the neural network testing.

             3. Sort the shot records by channel number (CHAN) instead of
                OFFSET.

             4. Some additional preprocessing may be necessary, such as True
                Amplitude Recovery, filtering, scaling. Test these processes until
                you can clearly see the first arrivals.

             5. Select to display 1 ensemble per screen and set the Display MODE
                to WT/VA instead of Grayscale for this application.

             6. Execute the flow.




Landmark                       ProMAX 3D Seismic Processing and Analysis            7-3
Chapter 7: Neural Net First Break Picking


                                 This flow is virtually identical to the flow that we used to pick the
                                 first break mute and decon design gate. You may want to copy the
                                 “pick parameter tables” flow to save some work.:

                           Editing Flow: 23- Neural Network Picking

                           Add              Delete        Execute           View        Exit

                           Disk Data Input
                                 Select dataset------------------------------”shots - 5 test shots”
                                 Trace Read Option------------------------------------------------Sort
                                 Select primary trace header entry------------------SOURCE
                                 Select secondary trace header entry ----------------- CHAN
                                 Sort order for dataset --1001,1014,1067,1071,1081:*/
                           True Amplitude Recovery
                                 Apply spherical divergence corrections ------------------Yes
                                 Basis for spherical spreading ---------------------------1/dist
                                 Apply inelastic attenuation corrections --------------------No
                                 Get TAR velocity function from db? -------------------------No
                                 Specify TAR velocity function ----------------------------
                                 --------------0-9000,500-11200,1200-12500,2000-14000
                                 Apply dB/sec corrections?-------------------------------------Yes
                                 dB/sec correction constant ---------------------------------------6
                                 Maximum application TIME --------------------------------2000
                           Automatic Gain Control
                                 The default parameters should be adequate
                           Trace Display
                                 Number of ENSEMBLES/screen -------------------------------1
                                 Trace Display MODE ---------------------------------------WT/VA




7-4             ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                            Chapter 7: Neural Net First Break Picking


           7. Zoom inside Trace Display from 0 to 600 ms on the trace for the
              first cable to get a more detailed look at the first breaks.




           8. Use the First Break Picker ¦ Set Neural Network Parameters...
              pulldown menu.

              Select a phase for the picker and a signal to noise window length. (A
              peak and a 100 ms. time window should work fine.)




           9. Click OK.

           10. From the FirstBreakPicker ¦ Create Training Data Set...
               pulldown menu.

              You will be prompted to enter a description name for a
              miscellaneous time gate to guide the NN picker. For example, you



Landmark                    ProMAX 3D Seismic Processing and Analysis            7-5
Chapter 7: Neural Net First Break Picking


                                can use a name similar to “NN GATE” to distinguish this time gate
                                from any other miscellaneous time gates.

                            11. Click OK.

                            12. Choose to interpolate the picked times as a function of AOFFSET
                                (the default).

                                A window appears with two tables present. The highlighted, active
                                table is called FB Training Data and the other refers to the above
                                miscellaneous time gate. The active table contains example first
                                arrival picks for the Network Training.




                                                NN FB Picking Open Tables

                            13. Pick some example first breaks.

                                These picks are used by the NN FB Pick Trainer as the example
                                picks for learning. Manually pick some first breaks on this cable of
                                this shot using MB1. (These picks are only retained in memory.) You
                                do not need to pick the entire shot.

                            14. Use MB3 to snap the picks to the nearest peak, trough, or zero
                                crossing.

                                Snap to the same phase as was selected in the NN parameter window
                                earlier (PEAK).

                            15. Select the time gate from the parameter table selection window



7-6             ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                   Chapter 7: Neural Net First Break Picking


               This is not from the picking pull down menu. The gate is already
               open in the table selection window.

               This will help guide the neural network picker when it attempts to
               locate the first break picks. Make the top of the time gate parallel to
               the trend of the first breaks, and put it about two wavelengths prior
               to the actual first arrivals. Click MB3, New Layer, and add the
               bottom part of the gate. Again, position this gate to lie about two
               wavelengths after the first arrivals

            Note:

            The neural net algorithm is very sensitive to the slope of the top gate, so make sure
            your slope is parallel to the slope of your first breaks.



                    Projection of the Time Gate




           16. Use the FirstBreakPicker ¦ Neural Network Training... pull
               down menu and enter a name to assign to the weight table.

               For example use a name like”wt1.”

           17. Click OK.




Landmark                        ProMAX 3D Seismic Processing and Analysis                      7-7
Chapter 7: Neural Net First Break Picking


                                The window will disappear for a few seconds. When the screen
                                refreshes the training will have completed.

                            18. Use the FirstBreakPicker ¦ Neural Net Recall ¦ Continuous
                                Recall... pull down menu.

                                This option will repick this shot record using the information in the
                                selected weight file.

                            You will be prompted to input a descriptive name for the generated
                            picks. These picks were made “from interactive training in T.D. using
                            wt1”. You will also be asked for 3 numbers:




                                                     NN Recall for Testing

                            •   The maximum trace to trace static, a value of 20 is reasonable.

                            •   The offset to start picking at, a value of 1400 ft is good.

                            •   The number of traces to use for a line fit. Since our picks are not
                                very good, a fairly large number, about 11, may help the picker.

                            19. Click OK.

                                The program is now picking all of the traces on this shot based on
                                what it learned during the training.



7-8             ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                             Chapter 7: Neural Net First Break Picking


           Do not worry if all the picks are not good; they won’t be. This is a very
           difficult record to pick.




                                      NN Testing Picks

              You should also notice a new parameter table in the list of open
              tables with the same name as you assigned in the previous window.

           20. Click Traffic Light icon to go to the next shot ensemble.

           21. From the First Break Picker pulldown menu, select
               FirstBreakPicker ¦ Neural Net Recall ¦ One time recall...

              The current shot ensemble is now picked. At this point you may elect
              to retrain the network using additional information. To do so, make
              sure that you select to edit the FB Training Data Parameter table,
              make more training picks, and then retrain the network.

           22. From the pulldown menus in Trace Display, select File ¦ Exit /
               Stop flow and exit from the Trace Display and stop the flow.

           23. Select Yes, to save your picks.

              Most importantly, we need to save the weight tables. The Neural
              Network picks are useless, since we only picked a few shots and the
              training picks are only in memory. The time gate can be saved for
              future reference if required.


Landmark                     ProMAX 3D Seismic Processing and Analysis            7-9
Chapter 7: Neural Net First Break Picking




Neural Network First Break Picking

                            When NN First Break Pick Training has completed successfully, a
                            fb_weight matrix file is saved for use by the neural network to pick all
                            of the shots on the line. This exercise uses the fb_weight matrix file to
                            pick first breaks for the whole dataset.

                            1. Alter the existing flow as follows:

                           Editing Flow: 23- Neural Network Picking

                           Add              Delete       Execute           View          Exit

                           >Disk Data Input<
                           Disk Data Input
                                 Select dataset------------------------”shots - with geom (1st)”
                                 Trace Read Option--------------------------------------------Get All
                           Disk Data Insert
                                 Select dataset-----------------------”shots - with geom (2nd)”
                                 Trace Read Option-------------------------------------------Get ALl
                           True Amplitude Recovery
                           Automatic Gain Control
                                 The default parameters should be adequate
                           >Trace Display<
                           NN First Break Picker
                                 Select weight matrix parameter file ---------------------- wt1
                                 Number of traces in median line fit--------------------------11
                                 Maximum trace to trace static --------------------------------20.
                                 Starting offset to determine fb pick slope ----------- 1400.
                                 Select time gate parameter file --------------------- NN GATE
                                 First break storage------------------- Header and Database
                                 4 digit ID to store pick time in the TRC----------------- 0001

                            2. In Disk Data Input, input the shot file for the first half of the project
                               before pre-processing.

                                 Make sure you reset the Trace read option to Get All.

                            3. Read the second half file in the Disk Data Insert.


7-10            ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                             Chapter 7: Neural Net First Break Picking


           4. Some preprocessing may be necessary, such as trace edits, filtering,
              or scaling. Apply the same preprocessing that you applied to the
              input of the NN First Break Pick Training in Trace Display.

           5. Select the NN First Break Picker parameters.

              Enter the FBWEIGHT file you generated in the previous flow and
              your first break time gate.

           6. Set the value for number of traces in median line fit.

              This parameter establishes a local slope of the first break picks by
              specifying the number of previous first break picks to fit a line. (In
              the interactive picking in Trace Display we used 11 traces)

           7. Enter a starting offset for the picker.

              Enter an offset with good signal-to-noise which doesn’t exhibit
              shingling of refractors. For this data, an XDBoffset value of about
              1400 ft. is adequate. (We used 1400 ft. in the interactive picking in
              Trace Display.)

           8. Execute the flow.

           9. Once the picker has finished, globally QC your first break picks by
              using a database 3D point cloud display.

              First go to the line level and start DBTools by clicking Database.
              Then, pull down Database ¦ XDB Database Display. Click 3D
              and generate a PointCloud display from the TRC order using SIN,
              OFFSET, PICK001.




Landmark                     ProMAX 3D Seismic Processing and Analysis           7-11
Chapter 7: Neural Net First Break Picking


                            The display should illustrate if your picks are consistent. The cursor
                            tracker can be used to find the SIN numbers which have anomalous
                            picks.




                                                   QC Plots of the FB Picks

                            10. You may also find an XYgraph to be useful.

                                Click 3D and generate an XYgraph display of TRC: OFFSET,
                                PICK0001, SIN




7-12            ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                         Chapter 7: Neural Net First Break Picking


      Using the First Break Pick Macro for QC
                     This exercise allows you to plot the first breaks on the trace data for QC
                     and editing.

                     1. Modify your previous flow to build the following flow:


                    Editing Flow: 23-Neural Network Picking

                    Add            Delete           Execute            View          Exit

                    >Disk Data Input<
                    >Disk Data Insert<
                    >True Amplitude Recovery<
                    >Automatic Gain Control<
                    >Trace Display<
                    >NN First Break Picking<
                    First Break Pick Macro*
                          Select dataset ---------------------------- shots - with geom (1)
                          Trace read option ------------------------------------------------ Sort
                          primary trace header entry -----------------------------------SIN
                          secondary trace header entry --------------------------- NONE
                          sort order for dataset --------------------------------------------- */
                          Database parameter ------------ TRC NN_PICK PICK0001
                          Bulk shift static --------------------------------------------------- 25.
                          Specify LMO velocity --------------------------------- 1001:9000
                          Specify END time ----------------------------------------------- 200.
                          Number of display panels ---------------------------------------- 5
                          Trace scaling option ----------------------------------- Individual
                          ------- remaining parameters can default-------

                     2. Toggle everything inactive and add the First Break Pick Macro.

                     3. Execute the flow.

                     4. Use the Picking ¦ Edit Header Values (first breaks)... pull down
                        menu select the FB_PICK (First Break pick time) from the trace
                        header to overlay on the shot records.

                          Edit the picks as required. (Don’t forget to “snap.”)




Landmark                                ProMAX 3D Seismic Processing and Analysis              7-13
Chapter 7: Neural Net First Break Picking




Importing First Break Picks

                            A good set of first break picks is available, if your results from the neural
                            network were not good.

                            In this exercise we will read a good set of picks from an ASCII file
                            directly into the TRC order database.


        ASCII Import of First Arrival Times
                            1. Open an XDB Database display window.

                                Select ASCII ¦ Get to work with an existing ASCII file.




                            2. Select the file as directed by your instructor. For example:
                               /misc_files/3d/nnpkdang.a_db.




7-14            ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                     Chapter 7: Neural Net First Break Picking


                       Select the NNPKDANG attribute from the right hand window.




                    3. After the plot is complete, click Cancel to dismiss the import
                       window.

                    4. Save the attribute to the database using the Database ¦ Save
                       option.


      QC the Imported Picks
                    This exercise quality controls the imported values.

                    1. Generate a 3D: Pointcloud plot of the imported picks using SIN as
                       the X axis, OFFSET as the Y axis and plot NNPKDANG on the Z
                       axis.

                    2. You may also find an XYGraph to be of some use.

                       Generate a 3D: XYGraph: TRC, OFFSET, NNPKDANG, SIN




Landmark                             ProMAX 3D Seismic Processing and Analysis           7-15
Chapter 7: Neural Net First Break Picking




7-16            ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                           Chapter 8
            Source Receiver Geometry Check
Source Receiver Geometry Check is used to check your geometry by using the first arrival times
to predict where the shots and receivers were positioned relative to the geometry definition.

Several attributes are written to the SIN and SRF databases. These values can be displayed from
the database for analysis.




Topics covered in this chapter:

                         t Source Receiver Geometry Check




Landmark                                    ProMAX 3D Seismic Processing and Analysis        8-1
Chapter 8: Source Receiver Geometry Check




Source Receiver Geometry Check

                         You will run Source Receiver Geom Check using first arrival times and
                         analyze the results written to the database.


       Example Flow
                         1. Build the following flow:

                        Editing Flow: 24 - Source Rec Geom Check

                        Add           Delete          Execute           View          Exit

                        Source Receiver Geom Check*
                              Select First Break Times ----- TRC NN-PICK NNPKDANG
                              Compute V1 from first break times? -----------------------Yes
                              Minimum Offset for analysis ---------------------------------600
                              Maximum Offset for analysis-------------------------------3000
                              Maximum Location Error -------------------------------------220.

                         2. Select Source Receiver Geom Check parameters, specifying your
                            first break picks from the TRC OPF.

                              These are the NNPKDANG picks that were imported earlier.

                         3. Set the maximum location error to 2 group intervals or 220 ft.

                         4. Use an offset range that is consistent for a refractor.

                         There are many ways to determine the offset range to use for the
                         analysis. You may elect to look at the first arrival times from the
                         database, or you may elect to analyze a display of traces that are offset
                         ordered from a shot.




8-2           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                    Chapter 8: Source Receiver Geometry Check


      Offset Range from First Break Pick Plot
                     1. From XDB generate a 3D: XYgraph: TRC : OFFSET,
                        NNPKDANG, SIN and measure the offset value for the consistent
                        refractor. Values of 600 to 3000 ft. seem reasonable.




                                                                         3000 ft



                                           600 ft




      Offset Range from Trace Display
                     1. Re-run the flow that we used to pick the parameter tables.

                        In this flow we selected 5 shots and displayed them as a function of
                        offset. From this display you can select an offset range over a
                        consistent refractor.




Landmark                              ProMAX 3D Seismic Processing and Analysis          8-3
Chapter 8: Source Receiver Geometry Check




                                            Offset Range from Trace Display


       Database Values
                             This process writes several attributes to the SIN and SRF databases.

                             XPREDICT - predicted X coordinate

                             YPREDICT - predicted Y coordinate

                             DPREDICT - Distance for survey data

                             VPREDICT - Velocity estimate over offset range selected

                             APREDICT - azimuth from survey to predicted coordinate

                             TPREDICT - average delay time




8-4           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                  Chapter 8: Source Receiver Geometry Check


      Analyze the Results using Simple Plots
                     1. From the database, generate a simple plot of SIN:XPREDICT and
                        XCOORD.

                     2. Repeat the plot for YPREDICT and YCOORD.

                     3. Repeat the previous plots from the SRF database.

                     4. You may also look at a graph of DPREDICT for the shots and
                        receivers.


      Analyze the Results using 3D Plots
                     1. From the database, plot a 3D: XYGraph: SIN: XPREDICT:
                        YPREDICT: DPREDICT.

                        This plot shows the predicted x,y coordinates for each shot location.
                        These are color coded by the distance that they were moved, relative
                        to the original x,y.

                        You can open the color bar to see which have moved the farthest.

                     2. Using the Display ¦ Source ¦ Control Points ¦ Black pull
                        down menu, overplot the source control points.

                     3. Using the Views pull down menu and the distance measure option
                        from the Double-fold icon, you can identify which shots have been
                        moved.

                        Make the DPREDICT plot dominant by using the Views ¦
                        Transparent ¦ Sin based Posting of DPREDICT pull down
                        menu, and then measure the distance from the Xpredict-Ypredict
                        point to the original shots using MB3 from the double fold icon.
                        Find the shot that is the correct distance from the new location.

                        Make the Shot Post plot current, and identify the station location.

                     4. This same sequence can be used for the receivers.

                        From these plots you can isolate possible candidate shots and
                        receivers needing attention. You might want to review the first break
                        picks on these shots and possibly re-examine them using Graphical
                        Geometry QC.




Landmark                              ProMAX 3D Seismic Processing and Analysis           8-5
Chapter 8: Source Receiver Geometry Check


                             If an x,y is actually incorrect in the database, you can correct the
                             appropriate shot or receiver and then re-bin and reload the trace
                             headers.




8-6           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                                              Chapter 9
                                                   Refraction Statics
This section covers the steps for calculating and applying 3D refraction statics. First break picks
are required as input into this process.

ProMAX offers two approaches to calculate refractions statics. The first approach, consisting of
3D Refraction Statics Model, Inversion, and Computation processes, works well on smaller
surveys with good first breaks while the second, Refraction Statics Calculation, works well on
large surveys, tolerates poorer first break picks, and does not require each shot to have first break
picks.

We first use the 3 module suite, 3D Refraction Statics Model, Inversion and Calculation approach
to generate a solution and then run the single Refraction Statics Calculation process to generate a
second solution. We use the refractor offset file picked and saved using 3D Refraction Statics
Model from the first exercise as input to Refraction Statics Calculation in the second exercise.
Then, we save the original elevation statics using XDB Database Display, and apply our refraction
statics using Datum Statics Apply.

Finally, we will generate a stack with refraction statics applied and compare it to our elevation
statics stack.




Topics covered in this chapter:

                           t 3D Refraction Statics Model, Inversion and Computation
                           t Coordinate-based Refraction Statics
                           t Archive Original Elevation Statics
                           t CDP Mean Static after Refraction Statics
                           t Refraction Statics Apply and Stack
                           t Comparison of Stacks with and without Refraction Statics




Landmark                                     ProMAX 3D Seismic Processing and Analysis              9-1
Chapter 9: Refraction Statics




Refraction Statics Overview

                            Promax 3D Refraction Statics computes statics corrections to a fixed
                            elevation datum. Starting with first break picks of the 3D data, there are
                            three modules that must be run to compute refraction statics: 3D
                            Refraction Statics Model, 3D Refraction Statics Inversion, and 3D
                            Refraction Statics Computation. The refraction statics result can then be
                            applied to the data by running the Datum Statics Apply process.

                            Note: The Datum Statics Apply process first checks to see if other statics
                            have been applied to the traces by an earlier processing step. If statics
                            had been applied, Datum Statics Apply first removes these statics,
                            returning the traces to their original recorded time reference. If these
                            previous statics also contained any hand statics or shot delay
                            corrections, they are also removed and should be reapplied.

                            Once First Arrival Times have been picked, there are three major 3D
                            refraction statics processes:

                            •   3D Ref Statics Model

                                assigns picks with offset ranges to refractors

                                assigns initial estimates of refractor velocities and intercept times

                                computes shot and receiver Delay Times

                            •   3D Ref Statics Inversion

                                computes an interval vs. depth model of the refractor layers by
                                inverting the first arrival times

                            •   3D Ref Statics Computation

                                computes shot and receiver statics through the computed interval
                                velocity vs. depth model

                            3D Refraction Statics Model
                            The 3D Refraction Statics Modeling tool displays a plan view of the shot
                            and receiver locations of the 3D survey in one window and the first
                            break picks as a function of offset in another window. As the cursor
                            moves along the plan view of the survey, the shot closest to the cursor
                            and the receivers that were live when the shot was fired are highlighted.


9-2             ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                          Chapter 9: Refraction Statics


           First break picks associated with that shot are displayed in the other
           window.

           You have the ability to capture the picks from several shots in the first
           break pick window. You can then draw straight line segments through
           the picks to identify the different refractor layers. This will identify the
           offset range associated with each refractor and provide initial estimates
           of refractor velocity and intercept time. You can repeat the procedure in
           other areas of the survey, creating an initial model. The output model
           values are stored in the database.

           3D Refraction Statics Inversion
           The results of the 3D Refraction Statics Modeling routine can be used
           as an initial estimate for the 3D Refraction Statics Inversion process.
           Three different inversion methods are available: conjugate gradient,
           algebraic reconstruction technique (ART), and back-projection.

           Conjugate gradient and algebraic reconstruction technique are iterative
           methods that produce delay times and refractor velocities. Conjugate
           gradient holds all the picks in memory at once; therefore, it will run out
           of memory for large 3D surveys. However, it is the faster and produces
           better results for noisy data than the Algebraic Reconstruction
           Technique. ART only holds a portion of the first break picks in memory;
           therefore, it is used for any size 3D survey.

           Back projection is a single step inversion process that is good for
           estimating long wavelength variations in delay times. It generates a
           good updated initial model for the other two inversion methods.

           3D Refraction Statics Computation
           The 3D Refraction Statics Computation process converts the delay
           times and refractor velocities generated by the inversion process into
           source and receiver static corrections. The static is computed as a
           vertical traveltime to a fixed elevation datum.




Landmark                     ProMAX 3D Seismic Processing and Analysis              9-3
Chapter 9: Refraction Statics




                                Table 5: 3D Refraction Inversion Methods
         METHOD                  PROCESS              ADVANTAGES               DISADVANTAGES

         Back Projection         Single Step          Fast                     Does not update
                                                                               velocities

                                                      Good for estimating
                                                      long wavelength          Not good for short
                                                      variations in delay      wavelength variations
                                                      times                    in delay times


                                                      Good as input to other
                                                      methods

         Algebraic               Iterative            Can be used for large    Slow
         Reconstruction                               datasets: uses little
         Technique                                    memory
                                                                               Not as good as
                                                                               conjugate gradient for
                                                      Resolves short and       noisy data
                                                      long wavelength in
                                                      delay times well for
                                                      clean data

         Conjugate Gradient      Iterative            Fast                     Memory intensive;
                                                                               restricted to smaller
                                                                               datasets
                                                      Resolves short and
                                                      long wavelength
                                                      variations in delay
                                                      times well for clean
                                                      and non clean data




9-4             ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                                     Chapter 9: Refraction Statics


      Refraction Statics Flow
                     1. Build the following flow:


                    Editing Flow: 25- refraction statics

                    Add            Delete           Execute           View         Exit

                    3D Ref Statics Model*
                          Select First Break Times ---- TRC NN_PICK NNPKDANG
                          Number of layers -----------------------------------------------------1
                          QC delay times ------------------------------------------------------No
                    >3D Ref Statics Inversion*<
                    >3D Ref Statics Computation*<

                     2. Select the 3D Refraction Statics Model parameters. Select your first
                        break picks file and enter one refractor layer for the model.

                     3. In the 3D Refraction Statics process, select No, the default, for QC
                        delay times.

                          This option can be used to QC your output delay times once they are
                          computed.

                     4. Execute the flow.


      3D Refraction Statics Model
                     1. Create the initial model by moving the cursor in the plan view
                        window. Click MB2 on a few shots in the 3D survey to select and
                        capture first break picks that will be interpreted for velocity and
                        offset ranges.

                      Note:

                      This project is very small. The recommended approach here is to
                      select about 5 shots. One in each corner and one in the center.


                     2. In the first break pick window, look at the options pulldown by

                          There are three options that can be used to draw a straight line
                          through a set of selected picks. The least square option (L2) is a good



Landmark                                ProMAX 3D Seismic Processing and Analysis             9-5
Chapter 9: Refraction Statics


                                choice. Select Options ¦ L2.

                            3. Select the offset range of interest for one refractor by clicking MB1
                               at the near offset and the MB2 ant the far offset. A line will be
                               drawn between them which is the Least Squares fit of all the points
                               in the selected offset range.




                                                L2

                                                                         Click MB3 to Save




                                           MB1




                                                                   MB2




                                                     Offset Range Picking

                            4. Save the offset range and velocity information by clicking MB3.

                                Notice the large asterisk appearing in the left hand screen at the
                                center of gravity of all the previously selected shots.

                            5. Exit and save the information to the database using the File ¦ Save
                               to Database and Exit pull down menu from either window.

                                This builds an offset range and initial refractor velocity vs. shot
                                location parameter table.


        QC the Delay Times
                            This exercise helps you review the quality of the delay times.



9-6             ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                            Chapter 9: Refraction Statics


           1. Select 3D Refraction Statics Model parameters to QC the delay
              times and execute the flow:

           Editing Flow: 25- refraction statics

           Add            Delete           Execute           View         Exit

           3D Refraction Statics Model*
                 Select First Break Times ---- TRC NN_PICK NNPKDANG
                 Number of layers -----------------------------------------------------1
                 QC delay times ----------------------------------------------------Yes
                 Select source delay ---------- SIN GEOMETRY DLY10000
                 Select receiver delay --------SRF GEOMETRY DLY10000
           >3D Refraction Statics Inversion*<
           >3D Refraction Statics Computation*<

           2. Execute the flow.

                 This time there should be two first break curves for each shot. A line
                 through one of these sets of picks should pass near to time 0 and




Landmark                       ProMAX 3D Seismic Processing and Analysis             9-7
Chapter 9: Refraction Statics


                                offset 0 if the Delay times are accurate.




                                                                    first break times adjusted
                                                                    by the delay times




                                             original first break
                                             times




                            3. Exit, but do not save the information to the database using the File
                               ¦ Exit without saving pull down menu from either window.




9-8             ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                                      Chapter 9: Refraction Statics


      3D Refraction Statics Inversion Parameterization
                     1. Toggle off 3D Refraction Statics Model and toggle on 3D Refraction
                        Statics Inversion:

                    Editing Flow: 25- refraction statics

                    Add            Delete           Execute           View          Exit

                    >3D Refraction Statics Model*<
                    3D Refraction Statics Inversion*
                          Select First Break Times ---- TRC NN_PICK NNPKDANG
                          Minimum pick weight -----------------------------------------------0
                          Layer number ----------------------------------------------------------1
                          Inversion method ------------------------- Conjugate Gradient
                          Get delay times from database------------------------------Yes
                          Select source delay ---------- SIN GEOMETRY DLY10000
                          Select receiver delay --------SRF GEOMETRY DLY10000
                          Get refractor velocity from database ----------------------Yes
                          Select refractor velocity ----- SIN GEOMETRY VEL10000
                          Get offset range from database ---------------------------- Yes
                          Select offset parameter file -------- Offset Range, Layer 1
                          Refractor cell width ------------------------------------------ 1000.
                          Refractor cell height ------------------------------------------1000.
                          Maximum # iterations --------------------------------------------75
                          Interactive mode? ------------------------------------------------- No
                          New database entry?---------------------------------------------No
                    >3D Refraction Statics Computation*<

                     2. Select the first break picks from the Trace database.

                     3. Specify layer one for your refractor layer.

                          For multi-layer models, the refractor layer must be specified and the
                          inversion process must be executed for each layer.

                     4. Enter the delay times, velocities and offsets generated by your
                        initial model.

                          All information is read from the database. Use the source velocities



Landmark                                ProMAX 3D Seismic Processing and Analysis              9-9
Chapter 9: Refraction Statics


                                for the refractor velocity.

                                The program uses these estimated velocities as the initial refractor
                                velocity in the inversion computation.

                            5. Select the default for refractor cell width and height, 1000 ft. by
                               1000 ft.

                                The refractor cell width and height refer to dimensions for a
                                rectangular grid of cells. The process looks for the refractor velocity
                                in this grid. Since the refractor velocity varies slowly, compared to
                                the weathering velocity, a cell size several times greater than the
                                station spacing is recommended.

                            6. Set the maximum number of iterations to 75.

                                This parameter provides an upper limit of iterations for the
                                conjugated gradient and ART techniques. If the solutions have not
                                converged (changing by less than one tenth of a ms) within this
                                number of iterations, the program will stop.

                            7. You can run this using the interactive QC capabilities but in general,
                               running automatically should be adequate.

                                Your instructor may demonstrate the interactive mode. But the final
                                run will be done using the batch mode.

                            8. Execute the flow.

                                The source and receiver OPFs will contain the output of 3D
                                Refraction Statics Inversion. You can manipulate this information
                                before computing refraction statics, using the available database
                                math tools. For example, you can smooth the refractor velocities.

                                For 3D smoothing of the surfaces you would need to run the




9-10            ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                                     Chapter 9: Refraction Statics


                          RUNAV1 function in the dbmath.exe program.


      3D Refraction Statics Computation Parameterization
                     1. Toggle 3D Refraction Statics Inversion off and the 3D Refraction
                        Statics Computation on:

                    Editing Flow: 25- refraction statics

                    Add            Delete           Execute           View         Exit

                    >3D Ref Statics Model*<
                    >3D Ref Statics Inversion*<
                    3D Ref Statics Computation*
                          Number of layers------------------------------------------------------1
                          Compute V0 from UPHOLE data-----------------------------Yes
                          Layer 1source delays ------- SIN GEOMETRY DLY10000
                          Layer 1receiver delays -----SRF GEOMETRY DLY10000
                          Refr 1 velocity at sources----SIN GEOMETRY VEL10000
                          Refr 1 velocity at rcvrs-------SRF GEOMETRY VEL10000
                          Final datum elevation----------------------------------------1400.
                          Replacement velocity -----------------------------------------9000.

                     2. We are working with a 1 layer model and will compute the shallow
                        (or V) velocity from the uphole times.

                     3. Enter the inversion solution output delay times and velocities for
                        the single layer refractor layer.

                     4. Make the elevation datum and refractor velocity the same as used in
                        Apply Elevation Statics.

                          Elevation = 1400 ft. --------- Velocity = 9000 ft./sec

                     5. Execute the flow.

                     6. View the static corrections in the database using XDB Database
                        Display.

                          These statics corrections are labeled S_RFSTAT and R_RFSTAT in




Landmark                                ProMAX 3D Seismic Processing and Analysis            9-11
Chapter 9: Refraction Statics


                                the source and receiver ordered database files.

                                You can plot the S_STATIC and the S_RFSTAT simultaneously to
                                compare the two sets of statics. Similarly you can plot R_STATIC
                                and R_RFSTAT at the same time.

                            Simple plots of S_STATIC vs. S_RFSTAT and R_STATIC vs.
                            R_RFSTAT are also useful.




                                         Elevation Static vs. Refraction Static Plot




9-12            ProMAX 3D Seismic Processing and Analysis                               Landmark
                                                            Chapter 9: Refraction Statics




Coordinate-based Refraction Statics

             ProMAX provides a coordinate-based refraction statics algorithm that
             computes refractor velocities and delay times, a near-surface depth/
             velocity model and travel-time corrections to the final datum from offset
             and first break information. There is also an option to edit first break
             pick files automatically. All of the preceding attributes are written to the
             database. Multiple layer models can be created, and refractor velocities
             and depths and velocities will be computed for each layer. The principle
             advantages to using this Refraction Statics module instead of the 3D
             Refraction Statics Model, Inversion, and Compute routines used in the
             first exercise is that it is:

             •   more robust for noisy first breaks,
             •   does not require first breaks for every shot, and it is
             •   disk-based instead of memory-based, so it works better on large
                 surveys.

             The principle disadvantages are that since it is disk-based it is also
             slower and that it does not offer any graphical displays to help you pick
             parameters or control quality. However, other ProMAX tools will help
             us perform these functions. The source and receiver static solutions are
             applied to the data in a future step, Datum Statics Apply.

             As a part of this exercise you will see that there are four ways to enter
             the refractor offset ranges. These are:

             •   User type in-manually enter SIN and refractor offset values.
             •   Mute file-input a Top Mute file picked in Trace Display.
             •   Offset file-use the same offset table that was picked in the
                 Refraction Statics Model flow (first exercise in the chapter).
             •   Compute offsets-allow the software to compute offsets using a line
                 segment fit algorithm.

             In this exercise you will use first-break pick times to calculate a near-
             surface model and travel-time corrections. This process calculates shot




Landmark                       ProMAX 3D Seismic Processing and Analysis            9-13
Chapter 9: Refraction Statics


                            and receiver refraction statics to shift to the final datum and updates the
                            database. Results of this exercise applied in the next exercise.

                            1. Edit the current “refraction statics” flow as follows:.


                           Editing Flow: 25 - refraction statics

                           Add            Delete           Execute           View          Exit

                           Refraction Statics Calculation*
                                 Select First Break Time--------TRC:NN_PICK NNPKDANG
                                 Number of layers -----------------------------------------------------1
                                 Identification number -----------------------------------------------1
                                 Minimum fold ----------------------------------------------------------1
                                 Shooting Geometry------------------------------------------------ 3D
                                 V0 Options ------------------ Compute V0 from uphole times
                                 INPUT REFRACTOR OFFSET? ------------------------------ Yes
                                   Refractor Offset specification---------------- OFFSET file
                                   Select offset parameter file ---- Offset Range, Layer 1
                                 COMPUTE REFRACTOR VELOCITIES?------------------ Yes
                                   Type of INITIAL velocity computation ------------- MEAN
                                   Smooth INITIAL velocities before output? ----------- Yes
                                   Length of INITIAL velocity smoother ------------------ 201
                                   Edit first break times?-----------------------------------------No
                                 COMPUTE DELAY TIMES? ------------------------------------ Yes
                                   TYPE of delay time ALGORITHM----------Gauss-Seidel
                                   Number of iterations ---------------------------------------------5
                                   Type of GS computation statistics------------------ MEAN
                                   Iterate refractor velocity? -----------------------------------Yes
                                   Smooth velocity between iterations? ------------------Yes
                                   Length of Velocity smoother-------------------------------201
                                 COMPUTE REFRACTOR DEPTH MODEL? ------------- Yes
                                   First Refractor Smoothing -------------------No Smoothing
                                 COMPUTE SOURCE and RECEIVER STATICS? ------ Yes
                                   Final datum Elevation ------------------------------------1400
                                   Replacement method ------------------------ User specified
                                   Replacement Velocity --------------------------------------9000
                                 COMPUTE RESIDUAL STATICS------------------------------Yes
                                   Number of iterations---------------------------------------------3
                                   Length of surface elevation smoother-------------------15
                                   Length of low frequency filter-------------------------------15


9-14            ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                        Chapter 9: Refraction Statics


           2. Select Refraction Statics Calculation parameters.

              Select the first break time to use for the statics decomposition. These
              time picks will be in the TRC OPF and will normally be of the type
              NNPICK. Select the picks that we read in from the ASCII file, the
              NNPKDANG picks. Enter the number of layers to model, in this
              case use one layer. The identification number will be 1 for the first
              run through the process. The shooting geometry is 3D.

           There are six steps to Refraction Statics Calculation* described in the
           menu. They may all be turned on for refraction statics computation or
           you may select to run one option at a time and view the output in the
           database.

           3. INPUT V0 and REFRACTOR OFFSET.

              In this exercise we’ll compute V0 from uphole times and choose the
              refractor OFFSET file that we picked when we performed the
              Modelling step.

              Three database entries are created in the SIN OPF:

              •   SIN REFR_OFF OFFPSS11 ---Near offset of refractor.
              •   SIN REFR_OFF OFFPSE11 ---Far offset of refractor.
              •   SIN VELOCITY V0INIT11 ----Weathering Velocity.

           4. COMPUTE REFRACTOR VELOCITIES

              With this subheading turned on a refractor velocity is calculated
              based on the first break times and the offset range from the previous
              step. Although you can smooth the velocity model in the menu, you
              may wish to look at your model in the database before smoothing.
              You could then either smooth in the database (useful to see
              immediate results of smoothing), or define a smoother in the menu.

              There is also an option to edit the first break picks automatically by
              setting a deviation from the median velocity described by the offsets.
              If any picks deviate more than the selected amount they will be
              killed, and set to NULL in a new first break picks database file TRC
              F_B_PICK FBPEDITX, where X is the run identification number.
              Only the good picks will be included in this file. Remember to




Landmark                    ProMAX 3D Seismic Processing and Analysis           9-15
Chapter 9: Refraction Statics


                                examine this edited file.

                                Three database entries are created.

                                •   CDP VELOCITY VCINIT11 -- CDP velocity for 1st refractor.
                                •   SIN VELOCITY VSINIT11 ----Source velocity for 1st refractor.
                                •   TRC F_B_PICK FBPEDIT1 ----Edited first break pick file.

                                These database attributes may be edited.

                            5. COMPUTE DELAY TIMES

                                Once CDP velocity is available, delay times for shots and receivers
                                may be computed. This is done by iteration, starting with source
                                delay time estimates, followed by receiver delay time estimates, and
                                (optionally) finalized by CDP velocity updating. Values are not
                                computed for any SIN, SRF or CDP that does not meet the minimum
                                fold (menu parameter) criterion. Once the decomposition is
                                complete for each refractor, these missing values are interpolated
                                based on X and Y.

                                Three database entries are created.

                                •   SIN DELAYTIM SDELAY11----Source Delay times.
                                •   SRF DELAYTIM RDELAY11--- Receiver delay times.
                                •   CDP VELOCITY VCFIN011---- Final CDP velocities.

                            6. COMPUTE REFRACTOR DEPTH MODEL

                                The depth model stage inputs delay times and refractor velocities in
                                CDP, interpolates refractor velocity into SIN and SRF, computes a
                                depth model for sources and another for receivers. Optionally, the
                                first refractor depth in SRF may be projected into CDP, smoothed,
                                projected back into SRF, V0 recomputed in SRF based on the
                                smoothed depths, new V0 projected from SRF to SIN, and finally




9-16            ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                     Chapter 9: Refraction Statics


             SIN and SRF depth models computed.

             Six database entries are created.

             •   SIN REFDEPTH SDEP_011---Source Refractor Depth.
             •   SIN VELOCITY VSFIN011 -- Final Source velocity for 1st
                 refractor.
             •   SIN VELOCITY V0FIN011 ---Final Weathering Velocity.
             •   SRF REFDEPTH RDEP_011--Receiver Refractor Depth.
             •   SRF VELOCITY VRFIN011- - Final Receiver velocity for 1st
                 refractor.
             •   SRF VELOCITY V0FIN011 ---Final Weathering Velocity.

           7. COMPUTE SOURCE AND RECEIVER STATICS

             The statics computation stage inputs refractor velocities and
             refractor depths, computes source and receiver depths the FINAL
             datum of 1400 feet and outputs static values. We have the choice of
             inputting a constant velocity or the bottom refractor velocity. For
             this exercise choose a user specified value of 9000 ft/sec.

             Two database entries are created.

             •   SRF GEOMETRY RSTAT00X --- Receiver statics.
             •   SIN GEOMETRY SSTAT00X ----Source statics.




Landmark                   ProMAX 3D Seismic Processing and Analysis         9-17
Chapter 9: Refraction Statics




Archive Original Elevation Statics

                            The Apply Refraction Statics process overwrites the original
                            S_STATIC and R_STATIC attributes in the database. If you want to
                            preserve these values to use later, make sure you copy them to another
                            attribute name in the database before running Datum Statics
                            Calculation.


        Copy S_STATIC to ORGSSTAT
                            This exercise copies the S_STATIC.

                            1. From the Database window, select to produce a simple plot from the
                               Database ¦ Get option.

                            2. Produce a plot of S_STATIC from the SIN database.

                            3. Select to generate a new plot by copying the S_STATIC plot. THis
                               can be done suing the New ¦ Copy pull down menu.




                            4. Enter a name such as ORGSSTAT (Original Shot Static) and
                               change the description if desired.

                            5. Click OK.




9-18            ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                              Chapter 9: Refraction Statics


                   6. Save the new attribute using the Database ¦ Save option.


      Copy R_STATIC to ORGRSTAT
                   This exercise copies the R_STATIC.

                   1. From the Database window, select to produce a simple plot from the
                      Database ¦ Get option.

                      Produce a plot of R_STATIC from the SRF database.

                   2. Select to generate a new plot by New ¦ Copy copying the
                      R_STATIC plot.

                      Enter a name such as ORGRSTAT (Original Receiver Static) and
                      change the description.

                   3. Save the new attribute using the Database ¦ Save option.




Landmark                            ProMAX 3D Seismic Processing and Analysis         9-19
Chapter 9: Refraction Statics




CDP Mean Static after Refraction Statics

        Datum Statics Calculation
                            Datum Statics Calculation has a refraction statics path. The difference is
                            that in the elevation statics path, shot and receiver statics are computed,
                            whereas in the refraction statics path, the statics already exist in the
                            database. The main function of Datum Statics Calculation in the
                            refraction statics path is to compute N_DATUM and C_STATIC based
                            on an elevation smoothing factor, a final datum elevation and a
                            correction velocity. Since the floating datum (smoothed elevation), the
                            final datum and the replacement velocity are unchanged, we do not need
                            to recalculate the C_STATIC. However, if any of these change, you
                            would need to run Datum Statics Calculation to update the CDP mean
                            static (C_STATIC) before applying the refraction statics.


        Datum Statics Apply
                            The Datum Statics Apply program uses refraction statics computed by
                            the 3D Ref Statics Computation* or Refraction Statics Calculation*
                            processes, along with C_STATIC from the database to compute
                            NMO_STAT and FNL_STAT. Whenever statics are applied, these
                            header entries are updated and the integer multiple of a sample period
                            portion of NMO_STAT is applied to the trace and the remainder is
                            written to NA_STAT to be applied later.

                            It is important to note that the Datum Statics Apply process first checks
                            to see if other statics have been applied to the traces by an earlier
                            processing step. If statics have been applied, Datum Statics Apply first
                            removes these statics returning the traces to their original recorded time
                            reference. Also, if previous statics contained any hand statics or shot
                            delay corrections, these statics are also removed and should be
                            reapplied.

                            The Datum Statics Apply process will be incorporated into the stack
                            flow in the next exercise in order to reduce the time spent reading the
                            trace datasets.




9-20            ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                           Chapter 9: Refraction Statics




Refraction Statics Apply and Stack

             In the next exercise we build a complex flow. The basic steps can be
             summarized as follows:

                •   Apply the datum statics and output shot data with refraction
                    statics applied.
                •   Apply Normal Moveout and the post-NMO mute.
                •   Reproduce traces and split the flow.
                •   Condition the first set of traces for Residual Statics and output
                    resampled, 8 bit shot dataset.
                •   Stack the second set of traces and output a stack volume with
                    refraction statics applied.

             As previously discussed, we apply the datum statics with the refraction
             statics solution in the stack flow to avoid re-reading the shot data
             multiple times. Reproducing the traces and splitting the flow allows us
             to condition the data for residual statics while we avoid re-reading the
             shot data yet another time. The shot data to be used in Residual Statics
             is resampled to an 8 msec sample period and saved in 8 bit format to
             reduce its size and improve performance. Next, we stack the other copy
             of the traces and output the refraction statics stack.

             We will then repeat these steps for the second half of the dataset and in
             the next exercise merge the stacks and compare the merged refraction
             statics stack with the merged elevation statics stack.




Landmark                       ProMAX 3D Seismic Processing and Analysis           9-21
Chapter 9: Refraction Statics


                            1. Copy the initial stack flow for the first half of the data and edit it to
                               create the following flow:

                           Editing Flow: 26-Stack-refr stat (1st)

                           Add           Delete          Execute           View         Exit

                           Disk Data Input
                           Datum Statics Apply
                           Trace Display Label
                           Disk Data Output
                           Normal Moveout Correction
                           Trace Muting
                           Reproduce Traces
                           SPLIT
                           Bandpass Filter
                           Automatic Gain Control
                           Resample/Desample
                           Disk Data Output
                           END_SPLIT
                           SPLIT
                           Stack 3D
                           Trace Display Label
                           Disk Data Output
                           END_SPLIT




9-22            ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                            Chapter 9: Refraction Statics




           Editing Flow: 26-Stack-refr stat (1st)

           Add            Delete           Execute           View         Exit

           Disk Data Input
                 Select dataset ---------------------shots - pre processed (1st)
                 Trace read option -------------------------------------------- Get All
           Datum Statics Apply
                 Src datum statics db parm----------SIN GEOM SSTAT001
                 Rec datum statics db parm--------SRF GEOM RSTAT001
                 CDP datum statics db parm-------CDP GEOM C_STAT02
           Trace Display Label
                 Trace label --------------------------------------- refr stat applied
           Disk Data Output
                 Dataset File Name ---------------------- shots - refr stat (1st)

           2. Read the first half of the shots file with preprocessing.

           3. Set the parameters for Datum Statics Apply. Choose the refraction
              statics solution you wish to apply to the data.

                 Recall that the shot and receiver refraction statics solutions from 3D
                 Ref Statics Model, Inversion, and Computation, are saved as
                 S_RFSTATIC and R_RSTATIC, respectively, while the shot and
                 receiver refraction statics solutions from Refraction Statics
                 Calculation are saved as SSTAT001 and RSTAT001.

                 Use the Refraction Statics Calculation solutions for the Source and
                 Receiver datum statics database parameters by selecting
                 SIN GEOMETRY SSTAT001 and
                 SIN GEOMETRY RSTAT001.

           4. Add Trace Display Label

                 Use text similar to “refraction statics.”

           5. Select the Disk Data Output parameters.

                 Output a new file, describing the volume as shot organized with
                 refraction statics applied for the first half of the data volume such as



Landmark                       ProMAX 3D Seismic Processing and Analysis            9-23
Chapter 9: Refraction Statics


                                 “shots - refr stat (1st).”


        Apply NMO, post-NMO Trace Mute and Split the Flow

                           Editing Flow: 26-stack-refr stat (1st) cont

                           Add            Delete           Execute           View         Exit

                           Normal Moveout Correction
                                 Direction for NMO application -------------------- FORWARD
                                 Stretch mute percentage ----------------------------------------- 0.
                                 Apply any remaining static during NMO?----------------Yes
                                 SELECT Velocity parameter file ----- imported from ascii
                           Trace Muting
                                 SELECT mute parameter file ----- post nmo mute (brute)
                           Reproduce Traces
                                 Trace grouping to reproduce -----------------------Ensembles
                                 Total number of datasets -----------------------------------------2
                           SPLIT
                                 Trace selection MODE ------------------------------------ Include
                                 Primary trace header - REPEAT (REPEATED ensemble)
                                 Secondary trace header ----------------------------------- NONE
                                 SPECIFY trace list --------------------------------------------------1/
                           Bandpass Filter
                                 The default parameters will be adequate
                           Automatic Gain Control
                                 The default parameters will be adequate
                           Resample/Desample
                                 Output sample rate -------------------------------------------------8.
                                 All other input variables ------------------------------DEFAULT
                           Disk Data Output
                                 Output Dataset Filename---temp-input to correlation (1)
                                 Trace sample format -------------------------------------------8 bit
                           END_SPLIT

                            6. In Normal Moveout Correction, select the velocity table that you
                               imported and set the stretch mute percentage to 0.0, thus disabling
                               it.



9-24            ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                          Chapter 9: Refraction Statics


           7. In Trace Muting, apply the post-NMO trace mute that you picked
              previously.

           8. Make 2 copies of each ensemble using Reproduce Traces.

           9. SPLIT the flow passing the first REPEATED copy.

           10. Bandpass filter and AGC the data using the default parameters.

           11. Resample the data to an 8 ms sample period.

           12. Output the conditioned, prestack dataset in 8 bit format. Use a
               dataset filename like “shots-input to correlation.”

           13. End the split.




Landmark                        ProMAX 3D Seismic Processing and Analysis         9-25
Chapter 9: Refraction Statics


        Stack the next of traces and output a refraction statics stack

                           Editing Flow: 26-Stack-refr stat (1st) (cont)

                           Add            Delete           Execute           View          Exit

                           SPLIT
                                 Trace selection MODE ------------------------------------ Include
                                 Primary trace header - REPEAT (REPEATED ensemble)
                                 Secondary trace header ----------------------------------- NONE
                                 SPECIFY trace list --------------------------------------------------2/
                           Stack 3D
                                 Enter name of host -----------------------------
                                 Operating system of host----------------- (as per instructor)
                                 Restart with an existing stack? ------------------------------No
                                 Minimum in-line number ------------------------------------------1
                                 Maximum in-line number ----------------------------------------26
                                 Minimum x-line number--------------------------------------------1
                                 Maximum x-line number -----------------------------------------79
                                 Exponent of normalization factor -------------------------- 0.5
                                 Number of normalization scalars per trace ----------- 100
                                 Apply final datum statics after stack? -------------------Yes
                                 Size of input trace memory buffer (MB)---------------------- 4
                                 Size of stack trace memory buffer (MB) ----------------------4
                           Trace Display Label
                                 Trace label --------------------------------------------- refr stat(1st)
                           Disk Data Output
                                 Output Dataset Filename--------------stack - refr stat (1st)
                           END_SPLIT

                            14. Split the flow again and pass the second REPEATED copy through
                                the stack path.

                            15. In Stack 3D, set the minimum and maximum lines to be contributed
                                to by this input dataset. (This should already be set from the
                                original flow to lines 1 - 26.)

                            16. In Trace Display Label, identify this as the refraction statics stack
                                for the first half of the project.



9-26            ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                         Chapter 9: Refraction Statics


           17. In Disk Data Output, output a stack with refraction statics for the
               first half of the project.

           18. End the SPLIT.

           19. Execute the flow.




Landmark                     ProMAX 3D Seismic Processing and Analysis           9-27
Chapter 9: Refraction Statics


        Run Stack3D on the Second Superswath
                            1. Copy the flow for the first half stack to a new flow for the second
                               half:

                           Editing Flow: 27-Stack-refr stat (2nd)

                           Add            Delete           Execute           View         Exit

                           Disk Data Input
                                 Select dataset --------------------shots - pre processed (2nd)
                           Disk Data Output
                                 Output Dataset Filename ----------- shots - refr stat (2nd)
                           Datum Statics Apply
                           Normal Moveout Correction
                           Trace Muting
                           Reproduce Traces
                           SPLIT
                           Bandpass Filter
                           Automatic Gain Control
                           Resample/Desample
                           Disk Data Output
                                 Output Dataset Filename --temp-input to correlation (2)
                           END_SPLIT
                           SPLIT
                           Stack 3D
                                 Minimum in-line number ----------------------------------------16
                                 Maximum in-line number ----------------------------------------42
                                 Minimum x-line number--------------------------------------------1
                                 Maximum x-line number -----------------------------------------79
                           Trace Display Label
                                 Trace label ------------------------------------------- refr stat (2nd)
                           Disk Data Output
                                 Output Dataset Filename ------------stack - refr stat (2nd)
                           End Split

                            2. Change the Disk Data Input file name to the shot organized file for
                               the second half of the project.




9-28            ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                         Chapter 9: Refraction Statics


           3. Change the first Disk Data Output to write a file of shot organized
              data after application of the refraction statics for the second half of
              the project.

           4. Change the file name in the second disk data output to reflect that
              the data is the input to the correlation process for the second half of
              the project.

           5. Edit the Stack 3D parameters to reflect the inlines that are
              contributed to by this input dataset.

              In this case the second file contributes to lines 16 through 42.

           6. Change the Disk Data Output file name to a refraction statics stack
              file for the second half of the project.

           7. Execute the flow.




Landmark                     ProMAX 3D Seismic Processing and Analysis           9-29
Chapter 9: Refraction Statics




Merging the Partial Stacks

                            In this exercise, we will execute a flow to stack merge the two “partial
                            stack” files into one complete CDP stack for the entire project.

                            The flow that we need to do this already exists. All we need to do is
                            change the input and output file names.

                            1. Edit the flow that you built to merge the 3D stacks.

                            2. In Disk Data Input, input the first half partial stack file after
                               refraction statics.

                            3. In the Disk Data Insert, input the second half partial stack file after
                               refraction statics.

                            4. In the Stack Merge 3D menu the parameters should not need to be
                               changed since the last execution.

                            5. Add a Trace Display Label and output the dataset to disk.




9-30            ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                            Chapter 9: Refraction Statics




           Editing Flow: 28- Merge refr stat stacks

           Add            Delete           Execute           View         Exit

           Disk Data Input
                 Select dataset ---------------------------- Stack - refr stat (1st)
                 Trace read option ------------------------------------------- Get All
           Disk Data Insert
                 Insertion Mode -------------------------------------------------- After
                 Select dataset --------------------------- Stack - refr stat (2nd)
                 Trace read option -------------------------------------------- Get All
           Stack Merge 3D
                 Enter name of host -----------------------------
                 Operating system of host----------------- (as per instructor)
                 Restart with an existing stack? ------------------------------No
                 Minimum in-line number ------------------------------------------1
                 Maximum in-line number ----------------------------------------42
                 Maximum x-line number -----------------------------------------79
                 Exponent of normalization factor -------------------------- 0.5
                 Number of normalization scalars per trace ----------- 100
                 Size of input trace memory buffer (MB)---------------------- 4
                 Size of stack trace memory buffer (MB) --------------------- 4
           Trace Display Label
                 Trace label --------------------------------------refr stat (merged)
           Disk Data Output
                 Output Dataset Filename---------stack -refr stat (merged)

           6. Use the Compare Inlines and Compare Crosslines flows to compare
              the results of refraction statics with the one made using elevation
              statics only.




Landmark                       ProMAX 3D Seismic Processing and Analysis            9-31
Chapter 9: Refraction Statics




9-32            ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                                  Chapter 10
                                    Statistical Trace Editing
Trace Statistics computes up to eight different representative statistics for individual traces and
writes them to the TRC database. The database entries are useful in obtaining statistical properties
of seismic traces. By averaging the statistics of a selected trace order, it is possible to estimate the
quality of source gathers, receiver gathers, and CDPs. Ensemble Statistics calculates these
ensemble averaged properties and writes them to the database for analysis.

These Statistics may be viewed using XDB or DBTools and with some display orientations,
selected traces can be presented to the screen for editing or other analysis.




Topics covered in this chapter:

                            t Trace Statistics
                            t Ensemble Statistics
                            t Editing Data with Statistics
                            t Editing Data with Statistics using DBTools and IDA




Landmark                                       ProMAX 3D Seismic Processing and Analysis            10-1
Chapter 10: Statistical Trace Editing




Trace Statistics

                             Utilizing the time information from previously picked first breaks,
                             Trace Statistics calculates up to eight different statistics for each input
                             trace. These statistics include:

                             •   TRC_AMPL: average trace energy

                             •   FB__AMPL: average first break energy

                             •   PRE_FB_A: average pre-first break energy

                             •   PRE_FB_F: average pre-first break frequency

                             •   T_SPIKES: Spikiness: the ratio of maximum magnitude sample to
                                 trace signal amplitude

                             •   FRQ_PEAK: dominant frequency based on a count of zero
                                 crossings within a signal window

                             •   FRQ_WIDE: frequency deviation based on statistical scatter of
                                 frequency estimates

                             •   AMPDECAY: estimated trace energy decay rate in db

                             In this exercise you will try to identify bad traces using Trace Statistics.
                             Based on the values computed for each trace, you will edit the data
                             volume to remove abnormal traces.




10-2            ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                     Chapter 10: Statistical Trace Editing


           1. Build the following flow:


           Editing Flow: 29- Trace Statistics

           Add            Delete          Execute            View         Exit

           Disk Data Input
                 Select dataset ----------------------------------- shots - first half
                 Trace read option -------------------------------------------- Get All
           Disk Data Insert
                 Select dataset --------------------------------shots - second half
                 Trace read option --------------------------------------------Get All
           Database/Header Transfer
                 Direction of transfer ------ Load TO trace headers FROM
                 Number of parameters ---------------------------------------------1
                 First database parameter--- TRC NN_PICK NNPKDANG
                 First header entry --------(FB_PICK) First break pick time
           Trace Statistics
                 Types of trace statistics to compute ----------- TRC_AMPL
                 -------------------FB_AMPL PRE_FB_A PRE_FB_F T_SPIKES
                 -----------------------------FRQ_PEAK FRQ_WIDE AMPDECAY
                 Use first breaks or time gate------------------ FIRST BREAK
                 Form of statistic output------ DATABASE and HEADERS
           Disk Data Output
                 Output Dataset Filename ---------------------------- shots - all

           2. In Disk Data Input and Disk Data Insert, input your shot data before
              any processing.

           3. In Database/Header Transfer, select your NNPKDANG first break
              picks from the database, located in the TRC OPF as an NNPICK
              type, to the trace headers. Select the First Break Pick Time header
              entry to store the first break pick times.

           4. In Trace Statistics, select the trace statistics to calculate. Select
              them all.

           5. Output a combined shot file for later use.

           6. Execute the flow.



Landmark                      ProMAX 3D Seismic Processing and Analysis               10-3
Chapter 10: Statistical Trace Editing




Ensemble Statistics

                             Seismic properties of the traces may be more pronounced when viewed
                             from an ensemble based perspective. In this exercise, you will calculate
                             ensemble statistics in a few different domains and find the domain
                             which display potential problems the best.

                             1. Edit the existing flow to calculate Ensemble Statistics to possibly
                                identify anomalous data in the SIN and/or SRF domains.

                            Editing Flow: 29 - Trace Statistics

                            Add            Delete         Execute          View        Exit

                            >Disk Data Input<
                            >Disk Data Insert<
                            >Database/Header Transfer<
                            >Trace Statistics<
                            >Disk Data Output<
                            Ensemble Statistics*
                            Ensemble Statistics*
                            Ensemble Statistics*
                            Ensemble Statistics*

                             2. Input a trace statistic such as, TRC_AMPL, or FRQ_PEAK to help
                                identify and describe the noisy traces.

                             3. Highlight SRF, SIN, and CDP domains to calculate average/mean
                                statistics.

                             4. Repeat for other statistics.

                                  Only one statistic can be averaged per program execution.

                             5. Execute the flow.

                             6. Exit the flow and select Database from the global parameter menu.
                                Select Display ¦ Get, and view the ensemble statistic information
                                in the SIN, SRF, and CDP OPFs.




10-4            ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                            Chapter 10: Statistical Trace Editing




Editing Data with Statistics

                     Now that you have identified some noise using different statistical
                     approaches, what would be a simple way to edit the data?


      Analyze the Results
                     1. Exit the flow and select Database from the global parameter menu.
                        Using DBTools go to the TRC order and double click on some of the
                        statistical attributes.

                        Note ranges of vales for each statistic for which you might elect to
                        kill the traces.

                     2. Build a flow which will use trace statistical entries to kill the bad
                        traces as outlined on the next page.

                     3. In Database/Header Transfer, select to move data attributes from
                        the TRC OPF to the trace headers.

                        For the trace header entry, select “user defined” and use the same
                        name as the database attribute.

                        You can transfer more than one set of values in the same step.

                     4. Select Trace Kill/Reverse parameters to kill the noisy data.

                        For example, if you use FRQ_PEAK, select FRQ_PEAK as the
                        primary trace header and in the trace list include 65-80. Select one
                        primary trace header for each Trace Kill/Reverse.




Landmark                               ProMAX 3D Seismic Processing and Analysis            10-5
Chapter 10: Statistical Trace Editing




                            Editing Flow: 30 trace kills by statistics

                            Add            Delete           Execute           View          Exit

                            Disk Data Input
                                  Select dataset --------------------------------------------- shots -all
                                  Trace read option -------------------------------------------- Get All
                            Reproduce Traces
                                  Trace groupings to reproduce -------------------- Ensembles
                                  Total number of datasets -----------------------------------------2
                            IF
                                  Trace selection MODE ------------------------------------ Include
                                  Primary trace header--------- REPEATED ensemble copy
                                  Secondary trace header-------------------------------------NONE
                                  SPECIFY trace list ----------------------------------------------------1
                            Trace Kill/Reverse
                            Trace Kill/Reverse
                            Trace Display Label
                            ELSEIF
                            Trace Display Label
                            ENDIF
                            Trace Display




10-6            ProMAX 3D Seismic Processing and Analysis                                       Landmark
                                                      Chapter 10: Statistical Trace Editing



           Editing Flow: 30 trace kills by statistics (cont

           Add            Delete           Execute            View          Exit

           Disk Data Input
           Disk Data Insert
           Reproduce Traces
           IF
           Trace Kill/Reverse
                 Trace editing MODE --------------------------------------------- Kill
                 Get edits from DATABASE ------------------------------------- No
                 PRIMARY edit list header word --------------------- t_spikes
                 SECONDARY edit list header word ------------------- NONE
                 SPECIFY traces to be edited --------------------------100-300
           Trace Kill/Reverse
                 Trace editing MODE --------------------------------------------- Kill
                 Get edits from DATABASE ------------------------------------- No
                 PRIMARY edit list header word --------------------- trc_ampl
                 SECONDARY edit list header word ------------------- NONE
                 SPECIFY traces to edit ---------200000000-1500000000
           Trace Display Label
                 Trace label ------------------------------------------------ with edits
           ELSEIF
                 Trace selection MODE ------------------------------------ Include
                 Primary trace header--------- REPEATED ensemble copy
                 Secondary trace header-------------------------------------NONE
                 SPECIFY trace list ----------------------------------------------------2
           Trace Display Label
                 Trace label ------------------------------------------------------- input
           ENDIF
           Trace Display
                 Header Plot Parameter -------------(TRC_TYPE) Trace type
                 Number of display panels ----------------------------------------2

           5. Execute the flow.




Landmark                       ProMAX 3D Seismic Processing and Analysis              10-7
Chapter 10: Statistical Trace Editing


                                 View the edited data with Trace Display. Check that the noisy data
                                 has been edited and you have not edited too many near offset traces.




                                           Example of shot record before and after edits

                                 The header plot of TRC_TYPE is a quick visual aid to tell you which
                                 traces have been edited. All traces with TRC_TYPE =2 were killed
                                 by the Trace Kill process.

                               NOTE:

                               In this example, the values for the editing were exaggerated for demonstration
                               purposes.




10-8            ProMAX 3D Seismic Processing and Analysis                                              Landmark
                                                   Chapter 10: Statistical Trace Editing




Editing Data using Statistics with DBTools and IDA

             Given the scenario where you may have several hundred shots, you may
             not want to have to look at each trace on each shot to determine if they
             needed to be edited. It may be more efficient to only be presented with
             the shots that have suspicious traces and then decide if these traces
             should be killed or not. Using DBTools in conjunction with IDA and
             Trace Display, this workflow is possible. In this workflow, we will
             select the anomalous traces on a DBTools display and then ask Trace
             Display to show only the shots which contain these traces. In this
             fashion you may only have to look at a few shots instead of several
             hundred. The challenge is to generate a display that can be used to
             isolate the “anomalous” traces based on their statistical values.

             This will be a somewhat complex workflow demonstrating the power of
             DBTools and IDA. You will eventually have at least two displays from
             DBTools:

             1) a 3D crossplot of TRC: TRC_AMPL, PRE_FB_A, TSPIKES color
             coded by AMPDECAY with histogram of FRQ_PEAK

             2) a shot location map

             working in conjuction with a Trace Display of shot gathers.

             The workflow will involve identifying anomalous traces in the DBTools
             display and then telling Trace Display to only show the shots that
             contain these anomalous traces.




Landmark                      ProMAX 3D Seismic Processing and Analysis            10-9
Chapter 10: Statistical Trace Editing


        Start Trace Display and IDA
                             1. Build the following flow:


                            Editing Flow: 31- Trace Kills using DBTools

                            Add            Delete            Execute            View          Exit

                            Disk Data Input
                                  Select dataset -------------------------------------------- shots - all
                                  Trace read option ------------------------------------------------ Sort
                                  Interactive Data Access? -------------------------------------- Yes
                                  Primary trace header entry -------- Source Index Number
                                  secondary header entry ------------------------------------- None
                                  Sort order list -------------------------------------------------------- */
                                  Presort in memory or disk ------------------------------ Memory
                            Trace Display
                                  Trace scaling option ------------------------------ Entire Screen

                             2. Read in the combined shots file using SORT mode and turning IDA
                                on.

                             3. Display 1 shot per screen computing one global scaler for all traces.
                                This may help visualizing anomalous traces easier.


        Start DBTools and generate two displays
                             1. Exit from the flow and start DBTools by clicking on the Database
                                option from the global menu. bar.

                             2. Generate a shot location map using the View ¦ Predefined ¦
                                Source Fold Map option.

                                  Change to a monochrome color scheme and select a color from the
                                  color palette.




10-10           ProMAX 3D Seismic Processing and Analysis                                          Landmark
                                               Chapter 10: Statistical Trace Editing


           3. Generate a 3D Crossplot from the TRC OPF using




              TRC_AMPL, PRE_FB_A, TSPIKES, AMPDECAY and
              FRQWIDE and the axes, color code and histogram respectively.




Landmark                   ProMAX 3D Seismic Processing and Analysis         10-11
Chapter 10: Statistical Trace Editing


                             4. Re-orient the display using the manual axis rotation icon so that the
                                T_SPIKES axis is coming directly out of the screen.




                                 In this configuration you can see a relationship between the traces
                                 that have both high amplitudes before the first arrivals and also a
                                 high overall RMS amplitude. These traces can be isolated using the
                                 polygonal selection icon.

                             5. Select a polygon that encompasses the anomalously high amplitude
                                traces on each axis simultaneously.Remember to double click to
                                close the polygon.

                             6. Project these points to the SIN domain and see that the shots that
                                contain these traces are highlighted on the shot location map.




10-12           ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                  Chapter 10: Statistical Trace Editing


           7. From the shot location map, “PD”, using the bow and arrow icon,
              only the shots of interest to the Trace Display. Page through the
              shots and look for the anomalous traces by combining the header
              plot and by looking at the trace amplitudes.




           8. Open a trace kill table in Trace Display and start adding traces to be
              killed to the kill list.

           9. The DBTools displays can be re-oriented to continue the analysis
              by cross plotting any combination of attributes.




Landmark                     ProMAX 3D Seismic Processing and Analysis          10-13
Chapter 10: Statistical Trace Editing




10-14           ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                            Chapter 11
                                               3D Residual Statics
There are two external model correlation autostatics processes: Cross Correlation Sum and
Gauss-Seidel. Both of these processes compute surface consistent statics based on trace
correlations with externally built stack model traces. These trace correlations are generated by
External Model Correlation. The correlation pick times are written to the TRC database. The
individual cross correlation traces are written to an output data file. As an option to using the
Cross Correlation Sum and Gauss-Seidel surface consistent statics decomposers, the correlation
pick times can be applied directly to the data as trim statics.

A typical 3D reflection residual statics job flow consists of five steps:

                          •   model building

                          •   correlation gate picking

                          •   correlation computation

                          •   statics computation

                          •   statics application

These steps are covered in this chapter.




Topics covered in this chapter:

                          t F-XY Decon Model Building
                          t Cross Correlation Gate Picking
                          t Cross Correlation Computation
                          t External Model Autostatics Computation
                          t Static Application and Comparison
                          t Eigen Stack Model Building




Landmark                                     ProMAX 3D Seismic Processing and Analysis        11-1
Chapter 11: 3D Residual Statics




F-XY Decon Model Building

                           In this exercise you will build a stack model to use as input to external
                           model correlation.

                           1. Build the following flow:

                                  This flow is very similar to a stack flow; therefore, you may copy one
                                  of your Refraction statics stack flows to save some work.


                          Editing Flow: 32- External Mod - FXY decon

                          Add              Delete          Execute           View         Exit

                          Disk Data Input
                                  Select dataset -----------------------stack - refr stat (merged)
                                  Trace read option --------------------------------------------- SORT
                                  primary trace header------------------- (ILINE_NO) 3D inline
                                  secondary trace header-------------- (XLINE_NO) 3D cross
                                  Sort order for dataset -------------------------------------------*:*/
                          F-XY DECON
                                  The default parameters will be adequate
                          Bandpass Filter
                                  The default parameters will be adequate
                          Automatic Gain Control
                                  The default parameters will be adequate
                          Resample/Desample
                                  Output sample rate -------------------------------------------------8.
                                  All other input variables ------------------------------DEFAULT
                          Trace Display Label
                                  Trace label ------------------------------------------------FXY decon
                          Disk Data Output
                                  Output Dataset Filename-------external model - FXY dec
                                  Trace sample format -------------------------------------------8 bit

                           2. In Disk Data Input, input your refraction statics stack dataset.

                                  Sort by inline number as primary sort and crossline number as
                                  secondary sort. Process all inlines and cross lines.


11-2           ProMAX 3D Seismic Processing and Analysis                                       Landmark
                                                     Chapter 11: 3D Residual Statics


           3. In F-XY Decon, use the default values for all parameters.

           4. Add a Bandpass Filter and AGC to the flow.

              In this case, we will want to add some cosmetic poststack processing
              so the frequency content and amplitude of the model traces match
              those of the input prestack data. The default parameters will be
              adequate.

           5. Add the Resample process to the flow.

              It is fairly common to band limit the data for correlation purposes in
              the residual statics sequence. Since the high frequencies have been
              limited you can usually resample the data to an 8 msec sample rate
              without losing any information.

           6. Add a label to the trace headers identifying this data as being the
              output from FXY decon.

           7. In Disk Data Output, enter an output dataset name describing this
              data as being the output from FXY decon and built specifically as
              an External model.

              Since the data is scaled we should be able to store that amplitudes as
              8 bit numbers to conserve disk space.

           8. Display a few lines to QC the model dataset using your Display
              Inlines flow. Your Inline comparison flow will not work since there
              is a difference in sample periods.




Landmark                     ProMAX 3D Seismic Processing and Analysis         11-3
Chapter 11: 3D Residual Statics




Cross Correlation Gate Picking

                           In this exercise, you will pick a correlation gate center time on a series
                           of inlines. This is not really necessary for this project, but we are
                           demonstrating the procedure for use with other projects.


       Procedure for Picking Statics Horizon
                           .
                               Xline number




                                                           Inline number

                                              Randomly picked Autostatics Horizon points

                           Given that you have picked horizon times at these locations, only the
                           area that falls within the outer polygon defined by these points will be
                           correlated.


11-4           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                       Chapter 11: 3D Residual Statics




              Xline number




                                         Inline number


                               Area that would be Correlated

           Traces falling within the limits of the outer polygon, defined by the
           picked locations, are correlated. Therefore, it is critical, for all CDPs to
           fall within the polygon. This is accomplished by picking the first and last
           CDPs on all picked lines and to pick the first and last lines.




Landmark                     ProMAX 3D Seismic Processing and Analysis            11-5
Chapter 11: 3D Residual Statics


                                             Minimum Picking Requirements




                              Xline number




                                                     Inline number

                                             Absolute minimum requirements


                           Given that autostatics horizon control points were picked at the
                           beginning and end of a series of lines, the entire CDP range is
                           surrounded by the outer polygon. In this case, all CDPs will be
                           correlated.

                           The absolute minimum number of points that must be picked is 4 (four),
                           the first and last CDPs on the first and last lines.

                           Additional lines can be picked as long as the first and last points on any
                           line are picked. Additional points can be added on the picked lines as
                           required to define the regional geology.




11-6           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                                   Chapter 11: 3D Residual Statics


                          This may be viewed in 3d also. Given a case where 4 points are picked,
                          only the CDPs that fall inside the diamond will be picked.




           Xline number




                                                                                    x




                                    Inline number
                                                  x                     x




                                       x




                                           3D View of Picking Requirements




Landmark                                   ProMAX 3D Seismic Processing and Analysis         11-7
Chapter 11: 3D Residual Statics


       Pick the Autostatics Correlation Gate
                           1. Build the following flow:

                           This flow is similar to the “display inlines” flow. You may elect to copy
                           that flow to save some work.


                          Editing Flow: 33- Pick correlation gate

                          Add              Delete           Execute           View        Exit

                          Disk Data Input
                                  Select dataset -----------------------stack - refr stat (merged)
                                  Trace read option --------------------------------------------- SORT
                                  primary trace header-------(ILINE_NO) 3D inline number
                                  secondary trace header-----(XLINE_NO) 3D crossline nu
                                  Sort order for dataset ----------------------1,10-30(10),42:*/
                          Bandpass Filter
                                  The default parameters will be adequate
                          Automatic Gain Control
                                  The default parameters will be adequate
                          Trace Display
                                  Number of ENSEMBLES / screen ----------------------------10
                                  Primary trace LABELING ---------------------------------- NONE
                                  Secondary trace LABELING ----------(ILINE_NO) 3d inline
                                  MODE of Secondary trace annotation ------------ Different

                           2. In Disk Data Input, input your most recent stack dataset.

                                  Sort the input to read all crosslines on lines 1,10-30(10) and 42. You
                                  will pick gate center information on the first, last and every 10th line
                                  in between.

                           3. Apply a filter, and scale for cosmetics.

                           4. In Trace Display, plot 10 ensembles and annotate Inline as Primary
                              and Xline as Secondary.

                           5. Open a parameter table to pick an autostatics horizon.

                                  You will select a gate width (300 ms is suggested) and a smash (11
                                  is the default and is irrelevant since we are using an external model).



11-8           ProMAX 3D Seismic Processing and Analysis                                       Landmark
                                                     Chapter 11: 3D Residual Statics


              You might want to think about a naming convention for these tables
              since you may elect to test a few different ones. One convention you
              might use is a gate number followed by a description:”

              “01 - 300 wide centered at 650”

           6. Pick a few points on each line, making sure you get the first and last
              CDP on each line.

           7. You may want to center the gate on the event at about 650 ms on all
              displayed lines.

              Remember, these gates are discreet CDP time values. You do not
              want a pick time at every CDP nor do you want to snap the picks.

           8. Exit Trace Display and Save the table using the File ¦ Exit/Stop
              Flow pull down menu.




Landmark                    ProMAX 3D Seismic Processing and Analysis          11-9
Chapter 11: 3D Residual Statics




Cross Correlation Computation

                           Keeping with the superswath theme, we have two separate datasets that
                           must be correlated. We could run both files into one correlation
                           execution, or we could run two flows simultaneously. It is much more
                           efficient to run the flows simultaneously (especially if more than one
                           machine is available). Also remember that the input data files that we
                           have available are shot-organized.


        Correlate the First Half
                           1. Build the following flow:

                          Editing Flow: 34- External Mod corr (1st)

                          Add              Delete          Execute           View        Exit

                          Disk Data Input
                                  Select dataset ------------------temp- input to correlation (1)
                                  Trace read option --------------------------------------------Get All
                          External Model Correlation
                                  Select model trace dataset ---------- external model - FXY
                                  Use autostatics horizon or gate file? ------------ HORIZON
                                  Select autostatics horizon file ---- 01- 300 wd - 650 (ish)
                                  Minimum live samples in a gate (percent) --------------- 50
                                  Maximum static shift --------------------------------------------- 36
                                  Write corr pick TIMES to database ------------------------ Yes
                                  Write corr pick AMPLITUDES to database -------------- Yes
                                  Write quality control estimates to database ----------- Yes
                                  Database mode --------------------------------------------------New
                                  Enter 4 digit ID number ------------------------------------- FX11
                          Disk Data Output
                                  Output Dataset Filename----------xcorrs FXY - gate 01 (1)
                                  Trace sample format -------------------------------------------8 bit

                           2. In Disk Data Input, input your filtered and scaled, preprocessed
                              shot-organized data with NMO and mute applied. We generated this
                              dataset in the Refraction Statics stack flow.



11-10          ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                                  Chapter 11: 3D Residual Statics


                     3. In External Model Correlation, input your model stack and
                        autostatics horizon file.

                         You can use the default values for most of the remaining parameters.
                         We will however manually specify a NEW value for the output pick
                         times and use a 4 digit code similar to FX11 which means FX model,
                         Gate 1, first half.

                     4. In Disk Data Output, enter an output dataset file.

                         Disk Data Output is needed to create a dataset that contains the
                         actual cross correlation traces for EMC Xcor Sum Autostatics.
                         There will be one correlation trace for every trace in your prestack
                         dataset falling within the bounds of the picked CDP locations.


      QC the Picks from the First Half
                     1. Make a simple plot using XDB of the TRMFX11 attribute from the
                        TRC database.




                                         Picks after the first correlation

                     Notice that picks only exist for the first half of the traces.




Landmark                                ProMAX 3D Seismic Processing and Analysis          11-11
Chapter 11: 3D Residual Statics


        Correlate the Second Half
                           1. Copy the first half correlation flow to build the following flow:


                          Editing Flow: 35- External Mod corr (2nd)

                          Add              Delete          Execute           View        Exit

                          Disk Data Input
                                  Select dataset ------------------temp- input to correlation (2)
                                  Trace read option --------------------------------------------Get All
                          External Model Correlation
                                  Enter 4 digit ID number ------------------------------------- FX12
                          Disk Data Output
                                  Output Dataset Filename----------xcorrs FXY - gate 01 (2)
                                  Trace sample format -------------------------------------------8 bit

                           2. In Disk Data Input, input your filtered and scaled, preprocessed
                              Shot organized data with NMO and mute applied. We generated
                              this dataset in the Refraction Statics stack flow.

                           3. In External Model Correlation, input your model stack and
                              autostatics horizon file.

                                  You can use the default values for most of the remaining parameters.
                                  We will however manually specify a NEW value for the output pick
                                  times and use a 4 digit code similar to FX12 which stands for using
                                  the FX model, Gate 1 for the second half.

                           4. In Disk Data Output, enter an output dataset file.

                                  Disk Data Output is needed to create a dataset that contains the
                                  actual cross correlation traces for EMC Xcor Sum Autostatics.
                                  There will be one correlation trace for every trace in your prestack
                                  dataset falling within the bounds of the picked CDP locations.




11-12          ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                                Chapter 11: 3D Residual Statics


      QC the Picks from the Second Half
                     1. Make a simple plot using XDB of the TRMFX12 attribute from the
                        TRC database.




                                       Picks after the second correlation

                     Notice that picks only exist for the second half of the traces.




Landmark                               ProMAX 3D Seismic Processing and Analysis         11-13
Chapter 11: 3D Residual Statics




Merge the Two Halves

                           In order to produce a single surface consistent solution for residual
                           statics, we must have all of the travel time estimates in a single attribute
                           to feed to the decomposition program.


        Merge the Two Attributes into a Single Continuous Set
                           1. Build the following flow:

                          Editing Flow: 36- merge pick attributes

                          Add              Delete          Execute           View        Exit

                          Database Parameter Merge*
                                  Enter number of parameters to merge -----------------------2
                                  DB INFOTYPE PARM 1 --------- TRC STATICS TRM_FX11
                                  Start location of PARM 1 ------------------------------------------ 1
                                  End location of PARM 1 ----------------------------------- 19848
                                  DB INFOTYPE PARM 2 --------- TRC STATICS TRM_FX12
                                  Start location of PARM 2 ------------------------------------------ 1
                                  End location of PARM 2 ------------------------------------19848
                                  Select type of merge ------------------------------------------ Mean
                                  Merged parameter information type ----------------- statics
                                  Merged parameter name -------------------------- TRMFXY01
                          Database Parameter Merge*
                                  Enter number of parameters to merge -----------------------2
                                  DB INFOTYPE PARM 1 --------- TRC STATICS QLT_FX11
                                  DB INFOTYPE PARM 2 --------- TRC STATICS QLT_FX12
                                  Merged parameter name --------------------------- QLTFXY01

                           2. Set the parameters for the first Database Parameter Merge.

                                  Here we will merge the TRMFX11 and TRMFX12 values into a
                                  single attribute TRMFXY01.

                                  The output attribute name was select to reflect that an FXY decon
                                  external model was used and the gate was gate number 01.



11-14          ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                             Chapter 11: 3D Residual Statics


                    3. The second merge combines the QLT values together.

                    4. Execute the flow.


      QC the merged values
                    Again, this is NOT something you would do with millions of traces.

                    5. Open the Database and produce a simple plot of the TRMFXY01
                       values by double clicking the attribute.

                       You should see a continuous plot with values for all traces.




                                                Merged Picks




Landmark                             ProMAX 3D Seismic Processing and Analysis        11-15
Chapter 11: 3D Residual Statics




External Model Autostatics Computation

                           This exercise computes statics using both the Cross Correlation Sum
                           and the Gauss-Seidel Autostatics processes.

                           1. Build the following flow:


                          Editing Flow: 37-Compute residual statics

                          Add             Delete          Execute          View        Exit

                          EMC Autostat: Gauss-Seidel*
                                  TRC database correlation ---- TRC STATICS TRMFXY01
                                  Statics partitioning iterations -------------------------------- 3
                                  Maximum source or receiver static ----------------------- 30
                                  Min trace offset MAGNITUDE -------------------------------- 0
                                  Max trace offset MAGNITUDE ---------------------- 999999
                                  Weight solutions by pick quality factors --------------- Yes
                                  Alpha trimmed mean percentage-------------------------- 40
                                  Length of CDP structure smoothing ------------------------ 3
                                  Dampen the structure term at low fold? --------------- Yes
                                  Create a NEW database entry for each run? --------- Yes
                                  Enter 4 digit ID number ----------------------------------- FX01

                           2. In Gauss-Seidel, select the TRC TRMFXY01 file generated by
                              External Model Correlation.

                           3. You can use the default values for most of the remaining parameters
                              but look up any parameters you do not understand in the helpfile.

                           4. We will output a NEW attribute to the database and give it a name
                              that reflects these statics as having originated from using the FXY
                              decon model and correlation gate number 1 (FX01).

                           5. Execute the flow.




11-16          ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                                Chapter 11: 3D Residual Statics


      Expand the Flow to Run the Xcor Sum Decomposition
                    The Xcor Sum decomposition requires the trace files that contain the
                    correlation traces. In our case we have two separate files that need to be
                    combined into a single file before decomposition.

                   Editing Flow: 37-Compute residual statics

                   Add            Delete          Execute           View        Exit

                   >EMC Autostat: Gauss-Seidel*<
                   Disk Data Input
                         Select dataset ------------------------ xcorrs FXY - gate 01 (1)
                         Trace read option --------------------------------------------Get All
                   Disk Data Insert
                         Select dataset -------------------------xcorrs FXY - gate 01 (2)
                         Trace read option --------------------------------------------Get All
                   Disk Data Output
                         Output Dataset Filename------- xcorrs FXY - gate 01 (all)
                         Trace sample format -------------------------------------------8 bit
                   EMC Autostat: XCor Sum*
                         Input correlations from Tape or Disk? ------------------ Disk
                         Select Dataset -----------------------xcorrs FXY - gate 01 (all)
                         First statics computation domain ------------------------- CDP
                         Second statics computation domain ----------------- Source
                         Third statics computation domain ----------------- Receiver
                         Fourth statics computation domain ------------------- NONE
                         Adjust corr by a previous SOURCE static ---------------- No
                         Adjust corr by a pervious RECEIVER static ------------- No
                         Adjust corr by a previous CDP RESID --------------------- No
                         Method for correlation summing ------ Min/Max Exclude
                         Maximum source or receiver static ------------------------- 30
                         Create a NEW database entry ------------------------------ Yes
                         Enter 4 digit ID number ------------------------------------- FX01

                    1. Read in the two cross correlation files that were output from the
                       correlation steps and merge them into a single disk dataset using
                       Disk Data Input, Disk Data Insert and Disk Data Output.

                    2. In XCor Sum, enter this merged correlation file.


Landmark                              ProMAX 3D Seismic Processing and Analysis          11-17
Chapter 11: 3D Residual Statics


                                  You can use the default values for the rest of the parameters but look
                                  up any parameters you do not understand in the helpfile.

                           3. We will output a NEW attribute to the database and give it a name
                              that reflects these statics as having originated from using the FXY
                              decon model and correlation gate number 1 (FX01).

                           4. Execute the flow.


        View the Results Using XDB
                           5. View the SRF and SIN database entries created by Gauss-Seidel
                              called SGEMFX01.

                           6. View the SRF and SIN database entries created by Xcor-Sum called
                              SPEMFX01.

                                  You can do both simple graphs and/or you may elect to generate
                                  some color contour plots using the Field option in the 3D display
                                  functions.




11-18          ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                        Chapter 11: 3D Residual Statics




Static Application and Comparison

             In this exercise, you will apply residual statics, create stacks, and
             compare them with the brute stack. We will also prepare the necessary
             prestack dataset for future processing. The only required prestack output
             from this flow is 8 ms 8 bit data on disk for velocity analysis.

             1. Copy the refraction statics stack flow for the first half of the data and
                edit it to create the following flow:.

            Editing Flow: 38- resid stat stack (1st)

            Add           Delete          Execute           View         Exit

            Disk Data Input
            Apply Residual Statics

            Reproduce Traces

            SPLIT
            Normal Moveout Correction
            Trace Muting
            Stack 3D
            Trace Display Label
            Disk Data Output
            END_SPLIT

            SPLIT
            Bandpass Filter
            Automatic Gain Control
            Resample / Desample
            Disk Data Output
            END_SPLIT

             This is a complex flow. The basic steps can be summarized as follows:

                  •   Apply the residual statics.
                  •   Apply Normal Moveout and the post NMO mute and produce a
                      stack of the data with the residual statics applied.
                  •   Select only the lines for velocity analysis



Landmark                       ProMAX 3D Seismic Processing and Analysis         11-19
Chapter 11: 3D Residual Statics


                                  •   Apply pre-velocity analysis processing and output a temporary
                                      dataset built specifically for velocity analysis. Read the first half
                                      shot file with preprocessing applied.


        Apply the Residual Statics and Reproduce the Traces:

                          Editing Flow: 38- resid stat stack (1st) cont

                          Add              Delete           Execute           View         Exit

                          Disk Data Input
                                  Select dataset ------------------------------shots - refr stat(1st)
                                  Trace read option -------------------------------------------- Get All
                          Apply Residual Statics
                                  Normal database entry naming mode?------------------- No
                                  Source residual static ---------- SIN STATICS SGEMFX01
                                  Receiver residual static ------- SRF STATICS SGEMFX01
                          Reproduce Traces
                                  Trace grouping to reproduce --------------------- -Ensembles
                                  Total number of datsets -------------------------------------------2

                           1. Input the shot organized dataset for the first half of the project that
                              has the refraction statics applied.

                           2. Apply the residual statics that were generated by the Gauss-Seidel
                              External Model Decomposition process.

                                  These are the SGEMFX01 values for the shots and receivers.

                           3. Use Reproduce Traces to make two copies of each ensemble.

                                  Once copy will be stacked. The other copy will be processed in
                                  preparation for velocity analysis.




11-20          ProMAX 3D Seismic Processing and Analysis                                       Landmark
                                                                   Chapter 11: 3D Residual Statics


      Stack the First Half of the Data

                     Editing Flow: 38 - resid stat stack (1st) (cont)

                     Add            Delete           Execute           View         Exit

                     SPLIT
                           Trace selection MODE ------------------------------------ Include
                           Primary trace header ------REPEAT (Repeated ensemble
                           Secondary trace header ----------------------------------- NONE
                           SPECIFY trace list --------------------------------------------------1/
                     Normal Moveout Correction
                           Direction for NMO application -------------------- FORWARD
                           Stretch mute percentage ----------------------------------------- 0.
                           Apply any remaining static during NMO?----------------Yes
                           SELECT Velocity parameter file ----- imported from ascii
                     Trace Muting
                           SELECT mute parameter file ----- post nmo mute (brute)
                     Stack 3D
                           Minimum in-line number ------------------------------------------1
                           Maximum in-line number ----------------------------------------26
                           Minimum x-line number--------------------------------------------1
                           Maximum x-line number -----------------------------------------79
                     Trace Display Label
                           Trace label -------------------------------------------resid stat(1st)
                     Disk Data Output
                           Output Dataset Filename-------------stack -resid stat (1st)
                     END_SPLIT

                      4. Split the flow and pass the first REPEATed copy through the stack
                         path.

                      5. In Stack 3D, set the minimum and maximum lines to be contributed
                         to by this input dataset. (This should already be set from the
                         original flow to lines 1 - 26.)

                      6. In Trace Display Label, identify this as the residual statics stack on
                         the first half of the project.

                      7. In Disk Data Output, output a stack with residual statics for the first
                         half of the project.

Landmark                                 ProMAX 3D Seismic Processing and Analysis           11-21
Chapter 11: 3D Residual Statics


                           8. End the SPLIT.


        Split the Flow and Output the Data for Velocity Analysis
                           Our first task here is to decide on the velocity locations. At this point we
                           are not exactly sure what we will be using for supergathers so we will
                           gather a couple of lines on either side of the velocity lines.

                                  79



                                  60




                      Xline 40
                      Number




                                  20




                                  1
                                       1    5         15       25              35     42
                                                       Inline Number


                                       Proposed CDP Center Positions For Analysis

                           We will choose to output the velocity lines and 2 lines on either side as
                           well. This will yield lines 3-7, 13-17, 23-27 and 33-37.




11-22          ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                        Chapter 11: 3D Residual Statics




           Editing Flow: 38- resid stat stack (1st) cont

           Add            Delete          Execute           View         Exit

           SPLIT
                 Trace selection MODE ------------------------------------ Include
                 Primary trace header--- REPEAT (REPEATED ensemble
                 Secondary trace header ----ILINE_NO (3d inline number
                 SPECIFY trace list ---------------2:3-7,13-17,23-27,33-37/
           Bandpass Filter
                 The default parameters will be adequate
           Automatic Gain Control
                 The default parameters will be adequate
           Resample/Desample
                 Output sample rate -------------------------------------------------8.
                 All other input variables ------------------------------DEFAULT
           Disk Data Output
                 Output Dataset Filename------temp - input to velanal (1)
                 Trace sample format -------------------------------------------8 bit
           END_SPLIT

           1. SPLIT the flow passing the second REPEAT copy.

                 In this SPLIT we will also select to only pass traces that contribute
                 to our proposed velocity lines. At this point we are not sure exactly
                 which lines we want so we will gather 5 lines around each of our
                 velocity lines (5, 15, 25 and 35).

           2. Apply a bandpass filter and AGC to the data.

           3. Resample the data to an 8 ms sample period.

           4. Output a pre-stack dataset with Bandpass Filter, and AGC applied
              that is ready for velocity analysis in 8 bit format.

           5. End the split.

           6. Execute the flow.




Landmark                       ProMAX 3D Seismic Processing and Analysis          11-23
Chapter 11: 3D Residual Statics


        Run Stack3D on the Other Superswath
                           1. Copy the flow for the first half stack to a new flow for the second
                              half:

                          Editing Flow: 39- resid stat stack (2nd)

                          Add              Delete          Execute           View         Exit

                          Disk Data Input
                                  Select dataset ----------------------------shots - refr stat (2nd)
                                  Trace read option -------------------------------------------- Get All
                          Apply Residual Statics
                          Reproduce Traces
                          SPLIT
                          Normal Moveout Correction
                          Trace Muting
                          Stack 3D
                                  Minimum in-line number ----------------------------------------16
                                  Maximum in-line number ----------------------------------------42
                                  Minimum x-line number--------------------------------------------1
                                  Maximum x-line number -----------------------------------------79
                          Trace Display Label
                                  Trace label ----------------------------------------- resid stat (2nd)
                          Disk Data Output
                                  Output Dataset Filename ----------stack - resid stat (2nd)
                          END_SPLIT
                          SPLIT
                          Bandpass Filter
                          Automatic Gain Control
                          Resample / Desample
                          Disk Data Output
                                  Output Dataset Filename ------temp - input to velanal(2)
                          END_SPLIT

                           2. Change the Disk Data Input input file name to the shot-organized
                              file or the second half of the project.

                           3. Edit the Stack 3D parameters to reflect the inlines that are
                              contributed to by this input dataset. In this case the second file
                              contributes to lines 16 through 42.


11-24          ProMAX 3D Seismic Processing and Analysis                                       Landmark
                                                   Chapter 11: 3D Residual Statics


           4. Change the Disk Data Output file name to be a file for input to
              velocity analysis for the second half of the project.

           5. Execute the flow.




Landmark                    ProMAX 3D Seismic Processing and Analysis       11-25
Chapter 11: 3D Residual Statics




Merging the Partial Stacks

                           In this exercise, we will execute a flow to stack merge the two “partial
                           stack” files into one complete CDP stack for the entire project.

                           The flow that we need to do this already exists. All you need to do is
                           change the input and output file names.

                           1. Re-edit the flow that we built to Merge the 3D stacks.

                           2. In Disk Data Input, input the first half partial stack file after residual
                              statics.

                           3. In the Disk Data Insert, input the second half partial stack file after
                              residual statics.

                           4. In the Stack Merge 3D menu the parameters should not need to be
                              changed for the last execution.

                           5. Add a Trace Display Label and output the dataset to disk.




11-26          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                         Chapter 11: 3D Residual Statics




           Editing Flow: 40- Merge 3d stacks

           Add            Delete           Execute           View         Exit

           Disk Data Input
                 Select dataset -------------------------- Stack - resid stat (1st)
                 Trace read option -------------------------------------------- Get All
           Disk Data Insert
                 Insertion Mode -------------------------------------------------- After
                 Select dataset ------------------------- Stack - resid stat (2nd)
                 Trace read option -------------------------------------------- Get All
           Stack Merge 3D
                 Enter name of host ----------------------------------------------------
                 Operating system of host----------------- (as per instructor)
                 Restart with an existing stack? ------------------------------No
                 Minimum in-line number ------------------------------------------1
                 Maximum in-line number ----------------------------------------42
                 Minimum x-line number--------------------------------------------1
                 Maximum x-line number -----------------------------------------79
                 Exponent of normalization factor -------------------------- 0.5
                 Number of normalization scalars per trace ----------- 100
                 Size of input trace memory buffer (MB)---------------------- 4
                 Size of stack trace memory buffer (MB) ----------------------4
           Trace Display Label
                 Trace label ------------------------------------resid stat (merged)
           Disk Data Output
                 Output Dataset Filename------stack -resid stat (merged)

           6. Use the Compare Inlines and Compare Crosslines flows 3D flows to
              compare the stack with residual statics to the stack with refraction
              statics.




Landmark                       ProMAX 3D Seismic Processing and Analysis           11-27
Chapter 11: 3D Residual Statics




Eigen Stack Model Building

                           Eigen Stack process uses the Eigen vector decomposition techniques to
                           isolate the primary component stack from a supergather of pre-stack
                           traces. Conceptually, the wavelet on the stack trace after eigen stack is
                           more similar to the wavelets on the prestack data than a conventional
                           stack. Theory says that all of the wavelets recorded from a reflection
                           point are the same. These wavelets are time shifted due to near surface
                           velocity variations. Typically we measure these time variations by cross
                           correlating the pre-stack traces with a stacked trace. The Eigen Stack
                           process attempts to make the stacked trace wavelet that is as similar as
                           possible to the wavelet of the pre-stack traces. This should improve the
                           cross correlation process.



                                               Input Traces on CDP with NMO applied




                  Conventional Stack
                    Model Trace




                    Eigen Stack
                                                     Principal Component input traces
                    Model Trace


                                                Eigen Stack Decomposition


11-28          ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                                  Chapter 11: 3D Residual Statics


      Build the Eigen Stack External Model
                     In this exercise you will build an Eigen stack model to use as input to
                     external model correlation.

                    Editing Flow: 41- External Mod - Eigen Stack

                    Add            Delete           Execute           View         Exit

                    Disk Data Input
                          Select dataset ---------------- temp - input to correlation (1)
                          Trace read option -------------------------------------------- Get All
                    Disk Data Insert
                          Insertion Mode -------------------------------------------------- After
                          Select dataset -----------------temp - input to correlation (2)
                          Trace read option ------------------------------------------- Get All
                    Inline Sort
                          Select new PRIMARY sort key ----------------------------- CDP
                          Select new SECONDARY Sort Key ------------------OFFSET
                          Maximum traces per output ensemble ---------------------16
                          Number of traces in buffer ----------------------------------7000
                    Eigen Stack
                          Mode ---------------------------------------------Output Eigenstack
                          Get matrix design gates from DATABASE --------------- No
                          SELECT Primary gate header word --------------------- CDP
                          SELECT Secondary gate header word ---------------NONE
                          SPECIFY matrix gate parameters ----------- 1:400-1200/
                          Type of Computations ? -------------------------------------- Real
                          Horizontal window width -----------------------------------------3
                          Number of iterations ------------------------------------------------0
                          Apply final datum statics after stack? -------------------Yes
                    Trace Display Label
                          Trace label ---------------------------------ext mod - eigen stack
                    Disk Data Output
                          Output Dataset Filename-------------ext mod - eigen stack

                     7. In Disk Data Input and Disk Data Insert, input your two shot
                        organized datasets that have been prepared for input to correlation.




Landmark                                ProMAX 3D Seismic Processing and Analysis           11-29
Chapter 11: 3D Residual Statics


                                  These files have NMO, mute, bandpass filter, and scaling applied
                                  and have been resampled to an 8 millisecond sample period.

                           8. Enter the Eigen stack parameters as shown.

                           9. In Trace Display Label, apply a header label.

                           10. In Disk Data Output, enter an output dataset.

                           11. Display a few lines to QC the model dataset using a Display inlines
                               or Inline comparison flow.




11-30          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                                             Chapter 12
           Velocity Analysis and the Volume
                                     Viewer
In this chapter, we will look at two ProMAX velocity tools: Velocity Analysis and the Volume
Viewer/Editor. These tools can interact with one another via the Pointing Dispatcher. In the next
exercises we will look at this interaction.

Prior to analyzing the velocities, we will precompute data for input into Velocity Analysis.
Precomputing improves the interactive performance of Velocity Analysis.




Topics covered in this chapter:

                          t 3D Supergather Generation and QC
                          t Precomputed Velocity Analysis
                          t Interaction with the Volume Viewer/Editor




Landmark                                     ProMAX 3D Seismic Processing and Analysis         12-1
Chapter 12: Velocity Analysis and the Volume Viewer




Velocity Analysis Introduction

                           Velocity Analysis provides comprehensive interactive velocity
                           analysis, velocity quality control, and velocity field modification
                           capabilities.

                           Velocity Analysis is a “socket tool”; therefore, preprocessing of data
                           can be performed in the same flow before passing the data on to
                           analysis. Velocity Analysis also allows random access to the dataset.
                           With this feature, you can go back to the previously processed
                           ensemble, rewind the data to the first CDP specified in the sort order for
                           dataset, or go to any CDP in the dataset by specifying a new sort order.

                           Velocity Analysis is used to quickly pick velocities with the semblance
                           option. More detailed velocity information can be obtained by turning
                           on the multi-function velocity strip option and the interval velocity
                           display. Choice of the analysis locations is initially determined by
                           selecting analysis locations using the 2D or 3D Supergather Formation
                           Macros. Picks can be made on either the semblance plots or the multi-
                           function velocity strips, and picks made on one display will appear on
                           the other display.

                           Velocity Analysis only processes single ensembles of data, such as
                           CDPs or groups of CDPs. Creating supergathers prior to Velocity
                           Analysis is often helpful. Supergathers must be defined in a processing
                           flow before input to Velocity Analysis or Velocity Analysis Pre-
                           Compute. The 2D and 3D Supergather Formation* Macros may be used
                           to combine many CDP’s along inlines or along inlines and crosslines.
                           This will permit Velocity Analysis to read the combined CDP’s for one
                           analysis as one ensemble of data.

                           Precomputing data at predefined locations is also supported to speed the
                           interactive session. When used in the precomputed mode, the process
                           reads in precomputed VA data, as opposed to standard CDP ordered
                           data. This precomputed data is generated using Velocity Analysis
                           Precompute. Preprocessing of data must be performed at the
                           precomputing step.

                           In the following exercises we will concentrate on the Offset Distribution
                           analysis to find good supergathers and then proceed with the velocity
                           analysis.




12-2           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                          Chapter 12: Velocity Analysis and the Volume Viewer




3D Supergather Generation and QC

                   You may elect to gather traces from consecutive inlines and crosslines
                   into one supergather. You may also choose to use only an inline set of
                   traces.

                   3D spatial supergathers may be formed by using 3D Supergather
                   Formation*.

                   In order to define the spatial supergathers, we need to supply the inline
                   and crossline centers as the analysis locations, and the number of inlines
                   and crosslines at each analysis location.




                       40




           Crossline
           Number




                       20




                                         5                               15
                                                Inline Number




Landmark                             ProMAX 3D Seismic Processing and Analysis          12-3
Chapter 12: Velocity Analysis and the Volume Viewer


       Supergather Generation and Offset Distribution QC
                           In this exercise, we will build supergathers using the 3D Supergather
                           Formation* process. Here we will QC the supergathers for trace content
                           and offset distribution prior to running the velocity analysis.

                           We will compare offset distributions for a 3x3 spatial supergather, a 5x5
                           spatial supergather and a 9x1 inline supergather.




12-4           ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                    Chapter 12: Velocity Analysis and the Volume Viewer


           1. Build the following flow:


           Editing Flow: 42-Velocity analysis

           Add            Delete           Execute           View          Exit

           Disk Data Input
                 Select dataset -----------------------temp- input to velanal (1)
                 Trace read option --------------------------------------------Get All
           Disk Data Insert
                 Select dataset -----------------------temp- input to velanal (2)
                 Trace read option --------------------------------------------Get All
           Disk Data Output
                 Output Dataset Filename-------------------------------------temp
                 Trace sample format -------------------------------------------8 bit
           3D Supergather Formation*
                 Read data from other lines/surveys? --------------------- No
                 Select dataset ----------------------------------------------------temp
                 Presort in memory or on disk? ----------------------- memory
                 Maximum CDP fold ------------------------------------------------16
                 Minimum center inline number --------------------------------- 5
                 Maximum center inline number ------------------------------ 35
                 Inline increment -----------------------------------------------------10
                 Inlines to combine ----------------------------------------------------3
                 Minimum center cross line number ------------------------- 20
                 Maximum center cross line number ------------------------ 60
                 Crossline increment -----------------------------------------------20
                 Crosslines to combine ----------------------------------------------3
           Inline Sort
                 PRIMARY sort key ---------------------------------------- SG_CDP
                 SECONDARY sort key ----------------------------------- OFFSET
                 Maximum number of traces per output ----------------- 300
           Trace Display
                 Number of ENSEMBLES per screen ------------------------ 15
                 Header Plot Parameter ---------------------------------- OFFSET
                 Primary trace LABELING ------------- ILINE_NO (3d inline)
                 Secondary trace LABELING ---------- XLINE_NO(3d xline)



Landmark                       ProMAX 3D Seismic Processing and Analysis             12-5
Chapter 12: Velocity Analysis and the Volume Viewer


                           2. Use Disk Data Input, Disk Data Insert and Disk Data Output to
                              combine the two files that were built as input to velocity analysis
                              into a single temporary file.

                           3. Select the 3D Supergather Formation* parameters.

                               Although 3D Supergather Formation* is labeled as a stand-alone
                               process (*), it does not output any data within the module. Therefore
                               an output tool such as Disk Data Output or a display tool such as
                               Trace Display or Velocity Analysis should follow the supergather
                               formation in the same flow.

                               The input file is the preprocessed file that we made specifically for
                               the velocity analysis in 8 bit format with filter and AGC applied. The
                               Maximum CDP fold is 16.

                               Define your supergathers to be centered at inlines 5, 15, 25, and 35
                               and at crosslines 20, 40, and 60. Combine 3 CDP’s along inlines and
                               crosslines. This will initially define a 3 by 3 “box” around the center
                               CDP.

                               Each spatial supergather generated by 3D Supergather Formation*
                               is assigned a different value of the new header word, SG_CDP.

                           4. Sort the data input SG_CDP ensembles with a secondary sort of
                              OFFSET.

                               This will allow us to alter the display of the supergathers so that we
                               can see the supergather effect in linear offset space

                               There will be approximately 300 traces per output ensemble after the
                               Supergather Bin sort.

                           5. Display the supergathers for QC.

                               Display 15 ensembles with ILINE_NO as the primary annotation
                               and XLINE_NO as Secondary Annotation. This will give a good
                               idea of which inlines and crosslines belong to each SG_CDP
                               ensemble.

                               Use the Header plot option in the menu to plot the trace offsets above
                               the supergathers. You should look for linearity of the offsets.

                           6. Experiment with different supergather parameters and see if any
                              work better than others to improve the offset distributions.



12-6           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                              Chapter 12: Velocity Analysis and the Volume Viewer


            Try using 1 inline and 9 consecutive CDP’s at each location.

            •   Minimum Line = 5
            •   Maximum Line = 35
            •   Increment =10
            •   Inlines to combine=1
            •   Minimum Xline =20
            •   Maximum Xline = 60
            •   Inc = 20
            •   Crosslines to Combine= 9

            Try a 5x5 CDP supergather at the same centers.




           Offset Distribution Comparison Plots




Landmark                 ProMAX 3D Seismic Processing and Analysis          12-7
Chapter 12: Velocity Analysis and the Volume Viewer




Precomputed Velocity Analysis

                           Preparing supergathers and performing Velocity Analysis interactively
                           on a large 3D survey may require a lot of time. Therefore, you may elect
                           to use Velocity Analysis Precompute to precompute the supergathers
                           and calculate the semblance values at predefined locations. This can
                           significantly speed up the interactive Velocity Analysis session,
                           especially when a large number of CDP’s are used to create the
                           supergathers.

                           Another advantage of using Velocity Analysis Precompute is that
                           precomputed data provides quicker use of the random access capability
                           available in Velocity Analysis. It also allows simultaneous use of the
                           Volume Viewer/Editor and the ProMAX 3D Viewer. The Volume
                           Viewer/Editor provides map (time slice) and vertical cross section
                           views of the velocity volume. The ProMAX 3D Viewer provided for a
                           3D cube rendering of the velocity volume. Through the use of a
                           “pointing dispatcher” or PD, the Volume Viewer/Editor will
                           automatically update the isovelocity volume display with the picks
                           made in Velocity Analysis.


       Run the Precompute
                           1. Expand the Velocity Analysis flow and edit it to include Velocity
                              Analysis Precompute and Disk Data Output.




12-8           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                    Chapter 12: Velocity Analysis and the Volume Viewer




           Editing Flow: 42-Velocity analysis

           Add            Delete           Execute           View          Exit

           3D Supergather Formation*
                 Select dataset ----------------------------------------------------temp
                 Use other parameters from before for lines and xlines
                 Inlines to combine ----------------------------------------------------1
                 Cross lines to combine ---------------------------------------------9
           Velocity Analysis Precompute
                 Number of CDPs to sum into gather -------------------------- 9
                 Apply partial NMO-to-binning---------------------------------Yes
                 Apply differential CDP mean statics-----------------------Yes
                 Absolute offset of first bin center ------------------------------ 0
                 Bin size for vertically summing offsets ----------------- 110
                 Maximum offset ------------------------------------------------ 4429
                 Minimum semblance analysis velocity ---------------- 7500
                 Maximum semblance analysis velocity ------------- 18000
                 Number of semblance calculations---------------------------50
                 Semblance sample rate (in ms) ------------------------------ 20
                 Semblance calculation window ------------------------------ 40
                 Number of stack velocity functions---------------------------13
                 Number of CDPs per stack strip---------------------------------9
                 Scale stacks by number of live samples summed----Yes
                 Method of computing velocity fctns------Top/base range
                   Velocity variation at time 0-------------------------------2000
                   Velocity variation at maximum time------------------5000
                 Get guide function from existing parameter table?---Yes
                   Velocity guide function table name----Imported ASCII
                 Maximum stretch mute percentage from NMO-----------30
                 Use absolute value of offset for stacking --------------- Yes
                 Maximum stretch percentage for NMO ---------------------30
                 Long offset moveout correction-----------------------------None
           Disk Data Output
                 Output Dataset Filename-------temp-velanal precompute
                 Trace sample format -------------------------------------------8 bit


Landmark                       ProMAX 3D Seismic Processing and Analysis             12-9
Chapter 12: Velocity Analysis and the Volume Viewer


                           2. Parameterize the supergather formation macro.

                               Define your supergathers to be centered at inlines 5, 15, 25, and 35
                               and at crosslines 20, 40, and 60. Combine 5 CDP’s along inlines and
                               crosslines. This will define a 5 by 5 “box” around the center CDP.
                               (Minimum inline=5, maximum inline=35, inline increment=10,
                               inlines to combine=1; minimum crossline=20, maximum
                               crossline=60, crossline increment=20, crosslines to combine=9).

                           3. Parameterize the Velocity Analysis Precompute.

                               Use 9 CDP gathers per CVS strip. Note: The gather is built from a
                               5x5 matrix, but the stack panels will be 3 traces from 3 consecutive
                               lines.

                               Use 0 for the offset of the first bin center and 110 for the offset bin
                               size.

                               Choose a velocity range from 8500 to 16000 ft/sec and create 21
                               panels.

                           4. Enter a new data set name in Disk Data Output.

                           5. Execute this flow.




12-10          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                Chapter 12: Velocity Analysis and the Volume Viewer


      Velocity Analysis
                     1. While the job is running, edit the flow to toggle everything off and
                        add Disk Data Input and Velocity Analysis.

                    Editing Flow: 42-Velocity analysis

                    Add             Delete             Execute              View           Exit

                    Disk Data Input
                          Select dataset ---------------------temp- velanal precompute
                          Trace read option ------------------------------------------------Sort
                          Interactive Data Access ---------------------------------------- Yes
                          primary trace header -------------------------------------SG_CDP
                          secondary trace header ------------------------------------NONE
                          Sort order for dataset ---------------------------------------------*/
                    Velocity Analysis
                          Select display DEVICE: -----------------------------This Screen
                          Is the incoming data Precomputed?: ----------------------Yes
                          Set which items are visible?------------------------------------No
                          Set semblance scaling and autosnap parameters?:--No
                          ---------------------------------------------------------------------------
                          Display horizon(s)?: -----------------------------------------------No
                          Use neural network velocity picker?: -----------------------No
                          Interact with other processes using PD?:-----------------Yes
                             Get guide function from existing param. table? ---Yes
                             Vel. guide function table : ------imported from ascii file
                          ---------------------------------------------------------------------------------
                          Maximum stretch percentage for NMO: --------------------30
                          Long offset moveout correction?:-------------------------NONE
                          Interval velocity below last knee: ------------------------------0
                          Table to store velocity picks: ----after resid stat b4 DMO
                          Copy picks to next location--------------------------------------No

                     2. In Disk Data Input, input the dataset from the Velocity Analysis
                        Precompute execution of the flow. Turn IDA on by going to SORT
                        mode. This will allow Velocity Analysis to communicate with the
                        Volume Viewer for Velocity field QC.




Landmark                                  ProMAX 3D Seismic Processing and Analysis                  12-11
Chapter 12: Velocity Analysis and the Volume Viewer


                           3. In Velocity Analysis, choose Yes for “Is the data precomputed?”.

                           4. Set the Velocity Analysis parameters.

                               When you first parameterize the Velocity Analysis process, a subset
                               of the parameters will be visible, so begin by setting the “global
                               parameters” highlighted in the flow. Be sure to create a table to store
                               velocity picks such as “after resid stat b4 DMO”.

                               Next, select Yes for “Set semblance scaling and autosnap
                               parameters” to display the semblance submenu. The default settings
                               will work fine so turn off the semblance submenu by clicking No for
                               Set semblance scaling and autosnap parameters. The submenu
                               parameter settings will be retained and used even though they are
                               not visible.

                           5. The parameter “Set which items are visible works” the same way.
                              Both the visibility and semblance parameters can also be changed
                              interactively from within the velocity analysis tool.

                           6. Use the previous velocity field as a guide.

                           7. Execute the flow and begin picking velocities in the Velocity
                              Analysis display.

                               The velocity semblance, a corresponding CDP supergather, and the
                               CVS strips are displayed.

                               Another available display is a peak semblance histogram with
                               interval velocities derived from the RMS picks

                           8. Begin picking a velocity table by using the Pick icon, and pick a
                              function.

                               As you pick velocities on the semblance plot, the picks are also
                               displayed on the CVS strips and the interval velocity plot is
                               modified. You may also pick velocities on the CVS strips.

                               Note the CDP, ILN, and XLN values that appear in the upper left
                               hand corner of the display. These provide the center CDP value, the
                               range of inlines and the range of crosslines included in the current
                               velocity analysis supergather. Your first velocity analysis center
                               should have values of CDP 336, ILN 3-7, and XLN 18-23.




12-12          ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                            Chapter 12: Velocity Analysis and the Volume Viewer


      Velocity Analysis Icons
                     •   Next ensemble: Proceed to and process the next ensemble in the
                         dataset. If you are currently processing the last ensemble in the
                         dataset, this button will rewind the data and bring up the first
                         ensemble.

                     •   Previous ensemble: Step backward one ensemble and process the
                         ensemble before the current ensemble. If you are currently
                         processing the first ensemble of the dataset, this button is “grayed
                         out” and does not do anything.

                     •   Rewind: Rewind the dataset and go back to the first ensemble as
                         specified in the sort order.



                     •   Point Dispatcher(PD) save and send the velocity picks in the
                         current ensemble to the Velocity Viewer/Editor.

                     9. After you pick the first location and move to the second you may
                        want to overlay the function that you just picked as a second guide.
                        You can do this by clicking on View ¦ Functions ¦ Ghost
                        functions ¦ Average of all CDPs. This will display the average of
                        all of the functions that have been picked in the output table to date.

                         Your velocity picks are automatically saved to an RMS velocity
                         ordered parameter file when you move from one location to the next
                         or Exit the program. You also have the option to save picks using the
                         Table/Save Picks option.


      Using the Volume Viewer
                     As you pick velocities along a line using the Velocity Analysis tool, you
                     may want to QC your new velocity field. This can be accomplished by
                     simultaneously viewing a color isovelocity display of the entire velocity
                     volume. The tool used for this is a standalone process called the Volume
                     Viewer/Editor, and should be executed while you are running Velocity
                     Analysis, as outlined below.




Landmark                               ProMAX 3D Seismic Processing and Analysis         12-13
Chapter 12: Velocity Analysis and the Volume Viewer


                           1. After picking one or two locations, iconify the Velocity Analysis
                              Window.

                           2. Return to the ProMAX User Interface. Build a new flow to run the
                              Volume Viewer/Editor.

                          Editing Flow: 43 - Velocity Field QC

                          Add            Delete            Execute            View         Exit

                          Volume Viewer/Editor
                                Work in Time or Depth---------------------------------------- Time
                                Unit System ------------------------------------------------Database
                                Surface Coordinates--------------------------------------ILN/XLN
                                Source of depth coordinate------------------------------ Volume
                                Source of surface coordinate limits------------------- Volume
                                --------------------------------------------------------------------------
                                Input Volume Type------------------ Stacking (RMS) Velocity
                                    Select input volume--------------after resid stat b4 DMO
                                Velocity volume reference datum---------------------Floating
                                --------------------------------------------------------------------------
                                Display poststack seismic data ------------------------------No
                                --------------------------------------------------------------------------
                                Interact with Velocity Analysis------------------------------ Yes
                                Display gather locations----------------------------------------Yes

                           3. Set the parameters for Volume Viewer/Editor.

                                Make sure you input the same velocity volume (table) that you are
                                currently using in Velocity Analysis.

                                Also, make sure you select Yes to “Interact with Velocity Analysis?”
                                This will enable the PD (pointing dispatcher) to communicate with
                                the Velocity Analysis already running.

                           4. Execute the flow containing the Volume Viewer/Editor, and return
                              to the Velocity Analysis display.

                                Two Volume Viewer/Editor windows will appear: ProMAX/Volume
                                Viewer: Map and ProMAX/Volume Viewer: Cross Section. You will




12-14          ProMAX 3D Seismic Processing and Analysis                                        Landmark
                              Chapter 12: Velocity Analysis and the Volume Viewer


           want to try different ways of arranging the windows on the screen
           until you have made an arrangement that is workable for you.

           The following diagram is one possible way to arrange the windows
           on the screen:




             Possible Window Arrangement

           If you have not yet picked any velocities in Velocity Analysis, the
           velocity displays will contain zero values and therefore the screen
           will be all blue and the velocity and space scales will be very large.
           If you have picked at least one velocity function, you will only see a
           vertical color variation in the Cross Section window.

           The Map window displays a time slice through the current velocity
           volume at the position of the heavy, gray line that appears in the
           Cross Section window. You can change the time slice by activating
           the “Select a horizontal slice” icon in the Cross Section window and
           clicking MB1 at the appropriate time in the Cross Section window.
           The Map window also displays an outline of your 3D survey grid.

           The Cross Section window displays a vertical cross section through
           the current velocity volume at the position of the heavy, gray line


Landmark                 ProMAX 3D Seismic Processing and Analysis         12-15
Chapter 12: Velocity Analysis and the Volume Viewer


                               that appears in the Map window. You can quickly change to a
                               vertical cross section oriented 90 degrees to the current Cross
                               Section display by clicking on the “Select the perpendicular slice”
                               icon. Clicking MB1 will alternately display perpendicular vertical
                               cross sections at the position of your cursor.

                               You can also change the vertical cross section in the Cross Section
                               window by activating either of the “Select a vertical slice” icons in
                               the Map window. Click MB1 in the Map window at the appropriate
                               position and the Cross Section window will be updated with the
                               velocity cross section at that position.

                           5. From the Cross Section window, click View, and then
                              Volume Display.

                               A “Volume Controls” window will appear. Click the Cross-section
                               Nodes and Map Nodes , then Ok. This will display symbols in the
                               Map window and vertical lines in the Cross Section window
                               indicating the positions of the Velocity Analysis centers already
                               saved to the velocity table. The locations of these symbols and lines
                               are referred to as nodes.

                               You may also want to reduce the search radius for functions to
                               display in the cross section view. For this project set the search
                               radius to about 200 ft.

                           6. In the Velocity Analysis window, pick or modify the velocity
                              function for the current location.

                               In the Velocity Analysis display, click on the “bow-and-arrow” icon
                               to send the information to the Volume Viewer/Editor.

                               The velocity displayed in Volume Viewer/Editor updates in response
                               to picks made in Velocity Analysis. You should now see a vertical
                               line in the Cross Section window and a circular symbol in the Map
                               window at the X, Y location of the velocity function just picked.

                           7. In the Velocity Analysis window, click on the “Process next
                              ensemble” icon, and pick the next analysis location.

                               When you are finished picking this new analysis location, click on
                               the “Process next ensemble” icon again. This will not only move you
                               to the next analysis location, but will automatically send the velocity
                               picks just made to the Volume Viewer/Editor displays.




12-16          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                     Chapter 12: Velocity Analysis and the Volume Viewer


                 You should now have many symbols/lines in the Map and Cross
                 Section windows. Your velocity field should also have changed color
                 slightly based on the velocity changes just added.

                 In either the Map window or the Cross Section window, click on the
                 “PD” icon.

                 Any Velocity Analysis CDP location can be easily retrieved or
                 deleted from Volume Viewer/Editor through the use of the mouse.
                 This allows random access to any of the precomputed and picked
                 locations.


           Velocity Analysis PD Tool:
              By activating this icon, you can select a CDP and send it to Velocity
              Analysis. This icon does not appear if No was selected for “Interact with
              Velocity Analysis?” in the Velocity Viewer/Editor menu.

                 With the “PD” icon activated, position the mouse cursor over a node.
                 The cursor should change from an “x” to an “o”. Click MB1 to
                 retrieve that velocity function into the Velocity Analysis display.
                 Clicking MB2 deletes that analysis location.

              8. Continue picking velocities in Velocity Analysis until you finish all
                 of the locations for this project.

                 Remember, you may either use the “bow-and-arrow” icon to send
                 the picks from Velocity Analysis to the Volume Viewer/Editor
                 displays for QC before moving to the next analysis location, or you
                 may move directly to the next ensemble and your previous picks will
                 be automatically sent to the Volume Viewer/Editor displays.

              9. To finish picking in Velocity Analysis, click on the File ¦ Exit/
                 stop flow pull down menu in the velocity analysis and the File ¦
                 Exit pull down in the Volume viewer.




Landmark                        ProMAX 3D Seismic Processing and Analysis         12-17
Chapter 12: Velocity Analysis and the Volume Viewer




12-18          ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                              Chapter 13
                                                       3D Dip Moveout
3D Dip Moveout (DMO) is a dip-dependent partial migration that transforms nonzero-offset
seismic data into zero-offset seismic data. This yields improved (dip independent) velocity
estimates, attenuates coherent noise, and improves lateral resolution. In this chapter we discuss
how to run DMO to Gathers 3D and DMO to stack 3D.




Topics covered in this chapter:

                          t Offset Binning Parameter QC
                          t DMO to Gathers 3D
                          t Parallel Processing Overview
                          t System Administration for Parallel Processing
                          t Using Dipvels for Zero Dip Velocity Estimate
                          t DMO Stack 3D
                          t Trace Kill and Start Time Reset




Landmark                                     ProMAX 3D Seismic Processing and Analysis         13-1
Chapter 13: 3D Dip Moveout




Offset Binning Parameter QC

                             DMO to Gathers 3D requires that offset binning be performed on the
                             data. This offset binning is included in the DMO to Gathers process; but
                             the proposed parameters must be checked before running the DMO.

                             In this exercise, you will look at the offset distribution using the 3D
                             display capabilities in the database, create DMO gathers, and prepare
                             them for input to DMO.


       Offset Binning Parameter Determination
                             We can combine the features of XDB and DBTools to help identify the
                             proper parameters for the offset Binning. To visualize the problem let’s
                             first generate two displays from DBTools.

                             1. Generate a predefined CDP fold map.

                                Change to a monochrome color map and choose a color of your
                                choice.

                             2. Generate a 2D Crossplot from the TRC order of OFFSET, CDP,
                                ILN, ILN

                             3. Using the rectangular selection icon, select a rectangle over all
                                CDP’s but for a very narrow range of offset.

                             4. Project this group of selected points to the CDP order. Notice that
                                the population is poor. Play with the width of the selection polygon




13-2          ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                         Chapter 13: 3D Dip Moveout


              in offset until you get good population in CDP space within an
              offset bin.




           From this exercise it is clear that we are in severe trouble here. It is
           virtually impossible to get good population in CDP space for this project
           without using very wide offset bins. A typical workflow here would be
           to use DBTools to get an estimate of the offset bin width and then use
           XYGraph to determine the offset bin minima and maxima and the
           number of offset bins required.

           5. From XDB, generate a 3D: XYGraph from the TRC OPF of
              OFFSET, CDP, ILN.

              This graph will show you the offset distribution of your entire 3D
              dataset. It can be used to help you determine an appropriate number
              of bins, and minimum and maximum offset. You can use these
              values when selecting DMO to Gathers 3D parameters.

           6. Change the color table to use the table called “contrast.rgb” using
              the Color ¦ Edit and File ¦ Open pull down menus.

           7. Zoom in and display 5 or 6 lines on the screen.




Landmark                     ProMAX 3D Seismic Processing and Analysis         13-3
Chapter 13: 3D Dip Moveout


                                Typically for land 3d surveys this analysis should be done on more
                                than one line.




                                                               offset bin
                                                               width




                                                Offset vs. CDP plot for 5 lines

                                From this plot we need to confirm how wide the offset bins need to
                                be to get good population in the offset volumes and to determine the
                                minimum and maximum offsets to enter into the DMO to Gathers
                                3D menu. Remember that our goal is to get at least 1 trace per CDP
                                per offset bin.

                                You can overlay a grid on this display, resize the bins to your
                                proposed DMO offset bin width to start analyzing the data for proper
                                bin width determination.

                             8. Click on the Grid ¦ Display pull down menu.

                                Nothing much happens except that the bin editing icons appear on
                                the left side of the screen.

                             9. Click on the Grid ¦ Parametrize pull down menu.



13-4          ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                        Chapter 13: 3D Dip Moveout


              A small dialog box will appear where you can change the
              characteristics of the grid.




                                                                       1660




           10. Change the value of the Y origin to a value near the bottom of your
               zoomed window. In this example we can set it to 1660 as shown in
               the previous diagram.

           11. Click the Green Light Icon.

              You should get some lines drawn on the XYgraph.


                                                                   zoom window



                                                      grid lines




Landmark                    ProMAX 3D Seismic Processing and Analysis         13-5
Chapter 13: 3D Dip Moveout


                             12. Zoom in on two lines.




                                                                            How wide does the
                                                                            offset bin need to be
                                                                            to get 1 trace per CDP?




                                                                             measure the
                                                                             “half diamond”
                                                                             distance




                                                   Half Diamond Explanation

                                Here we must decide on the offset bin width. One way to do this is
                                to measure the “half diamond” distance using the “double fold” icon
                                MB3 function.

                                You should measure values around 600 or 700 ft. Given our group
                                interval is 110 ft. Let’s try an offset bin width of 660 ft. and see what
                                results we get. i.e. how many offset bins and population in the bins.

                             13. Click on the Grid ¦ Parametrize pull down menu.

                                Set the Cell Size across Azimuth to 660 ft. and click the green light
                                icon.

                             14. Move the Grid with so that the edge of the first bin is at 0 offset.




13-6          ProMAX 3D Seismic Processing and Analysis                                       Landmark
                                                        Chapter 13: 3D Dip Moveout


           This gives us reasonable coverage within the offset bins, but the far
           offset volume is very sparsely populated and we only have 6 live offset
           planes. This will yield 6 traces per CDP after 3D DMO to Gathers.




                         1       2       3        4       5        6




                                6 Offset Bins of 660 ft each

              For our purposes we will set the offset bin increment to 440 in order
              to run through the mechanics of the DMO to GATHERS. It is
              obvious now that it would be geophysically incorrect to run the
              DMO to Gathers with these parameters and that a width of 880 ft.
              would actually be required.

           15. Reset the Grid parameters by clicking on the Grid ¦ Parametrize
               pull down menu.

              Set the Cell Size across Azimuth to 440 ft. and press the green light
              icon.




Landmark                     ProMAX 3D Seismic Processing and Analysis         13-7
Chapter 13: 3D Dip Moveout


                             16. Move the Grid with so that the edge of the first bin is at 0 offset.




                                Min Offset = 0                                Max Offset = 4400


                                                        440 ft Offset bins

                             17. Move the cursor to the first line and read off the offset. It should be
                                 ZERO. Move the cursor to the line past the end of the live data. It
                                 should be 4400 ft.

                             18. Count the number of bins. There should be 10.

                                The minimum offset, maximum offset, offset bin width and number
                                of bins are the parameters that we need for DMO to Gathers 3D.

                             19. Exit from the XYgraph using the File ¦ Exit ¦ Confirm pull
                                 down menu.




13-8          ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                           Chapter 13: 3D Dip Moveout




DMO to Gathers 3D

            DMO to Gathers 3D is a constant velocity DMO process that
            accumulates the DMO response of each trace in a partial stack indexed
            by CDP, inline location, crossline location, and offset. This process uses
            an Integral (Kirchhoff) method with care taken to avoid spatial aliasing
            the DMO operator.

            There are many different alternatives that you can use at this point in the
            flow. The following questions will help us choose one:

            Which velocity lines do you want to resolve in this job?
               •   Lines 5,15 25 and 35

            Which input data files do you need to resolve these lines?
               •   Both superswaths

            Do you want to do spatial supergathers or inline supergathers?
               •   Inline supergathers

            Are you running on an SMP machine and do you need to
            parallelize the pre-processing as well as the DMO?
               •   This will vary depending on where the course is being taught.

            Have you adequately allocated scratch space?
               •   This project is small and you should have enough scratch
                   allocated to output 4 lines of 79 crosslines and 10 traces per CDP.

            Are you going to parallelize the DMO?
               •   No parallelization will be used (depends on available hardware
                   at the class site).




Landmark                      ProMAX 3D Seismic Processing and Analysis           13-9
Chapter 13: 3D Dip Moveout


                             1. Build the following flow to run DMO to Gathers 3D:


                         Editing Flow: 44-DMO to Gathers

                         Add              Delete           Execute           View         Exit

                         Disk Data Input
                                 Select dataset ----------------------------- shots - refr stat (1st)
                                 Trace read option -------------------------------------------- Get All
                         Disk Data Insert
                                 Insertion Mode -------------------------------------------------- After
                                 Select dataset ----------------------------shots - refr stat (2nd)
                                 Trace read option -------------------------------------------- Get All
                         Apply Residual Statics
                                 Normal database entry naming mode?------------------- No
                                 Source residual static ---------- SIN STATICS SGEMFX01
                                 Receiver residual static ------- SRF STATICS SGEMFX01
                         Normal Moveout Correction
                                 Direction for NMO application -------------------- FORWARD
                                 Stretch mute percentage ----------------------------------------- 0.
                                 Apply any remaining static during NMO?----------------Yes
                                 SELECT Velocity parameter file ----- after resids b4 dmo
                         Trace Muting
                                 SELECT mute parameter file ------ post nmo mute (brute
                         DMO to Gathers 3D
                         Trace Display Label
                         Disk Data Output
                         Normal Moveout Correction
                         Trace Display Label
                         Disk Data Output

                             2. In Disk Data Input and Disk Data Insert, input the two shot
                                organized files with refraction statics applied.

                             3. Apply the residual statics that were generated by the Gauss Seidel
                                External Model Decomposition process.

                                These are the SGEMFX01 values for the shots and receivers.




13-10         ProMAX 3D Seismic Processing and Analysis                                        Landmark
                                                            Chapter 13: 3D Dip Moveout


           4. In Normal Moveout Correction, select your best RMS velocity
              field:

           Editing Flow: 44-DMO to Gathers (cont)

           Add            Delete          Execute           View         Exit

           DMO to Gathers 3D
                 Enter name of host -----------------------------
                 Number of worker threads --------------------------------------- 1
                 Minimum in-line number ------------------------------------------5
                 Maximum in-line number ----------------------------------------35
                 in-line number output sampling interval ------------------10
                 Minimum x-line number--------------------------------------------1
                 Maximum x-line number -----------------------------------------79
                 x-line number output sampling interval ---------------------1
                 Number of consecutive gathers to output at each loc --1
                 Typical CDP spacing in ensembles---------------------------55
                 Minimum offset to retain -------------------------------------------0
                 Maximum offset to retain ------------------------------------4400
                 Number of offset bins ---------------------------------------------10
                 Offset sampling ---------------------------------------------OFFSET
                 Typical mute time at largest offset ----------------------1000
                 Typical RMS velocity at early times ---------------------9000
                 Apply v(z) correctoin? ---------------------------------------------No
                 Amplitude and phase balancing mode ---use exponent..
                 Exponent of normalization factor -------------------------- 0.5
                 Number of normalization scalars per trace ----------- 100
                 Re-kill dead traces and apply stack mutes ------------- No
                 Size of input trace memory buffer (MB)-----------------------4
                 Size of stack trace memory buffer (MB) ----------------------4

           5. Apply the post NMO muteSelect the DMO to Gathers parameters.

                 In DMO to Gathers 3D, leave host name blank.

                 Host name refers to the name of the hosts, or nodes, where you
                 would like to run the program. This program is set up to run in



Landmark                      ProMAX 3D Seismic Processing and Analysis           13-11
Chapter 13: 3D Dip Moveout


                                parallel (on more than one machine). If no host name is specified, the
                                process executes on the same node as the ProMAX executive.

                                Make the crossline number sampling interval 1 and the inline
                                number sampling interval increment by a sampling interval for
                                performing velocity analysis. In this case, use 10 to output every
                                tenth inline starting at 5 and ending at 35.

                             6. Set the CDP spacing is 55 ft.

                             7. Set the number of offset bins to 10 and the offset range to start at 0
                                ft. and end at 4400 ft.

                                The number of offset bins parameter governs the number of output
                                traces per CDP.

                             8. Values of 1000 ms mute time at far offset and 9000 ft./sec shallow
                                velocity is satisfactory.

                             9. Specify 100 for the number of fold normalization scalers per trace.

                                The number of fold normalization scalars parameter controls the
                                time interval for which a record of the time-variant fold at each CDP
                                is maintained. Greater numbers better preserve relative amplitudes,
                                but the program runs longer.

                             10. Do not rekill or remute the output traces.

                             11. Default the size of memory buffers and the number of ensembles
                                 per page parameters.




13-12         ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                           Chapter 13: 3D Dip Moveout


                 The size of memory buffers parameters are available to maximize
                 the efficiency of the program. Try to NEVER allow (stack buffer +
                 2*input buffer) > 1/2 machine memory..

           Editing Flow: 44-DMO to Gathers (cont)

           Add            Delete          Execute           View         Exit

           Trace Display Label
                 Trace label ------------------------------------------------nmo - dmo
           Disk Data Output
                 Output Dataset Filename -------------dmooffs - nmo - dmo
           Normal Moveout Correction
                 Direction for NMO application -----------------------INVERSE
                 SELECT Velocity parameter file -- ---after resids b4 dmo
           Trace Display Label
                 Trace label --------------------------------------------nmo dmo nmi
           Disk Data Output
                 Output Dataset Filename---------dmooffs - nmo dmo nmi

           12. Add a Trace Display Label and Disk Data Output to label and
               output the data after the DMO.

                 This output data can be stacked for an intermediate product to QC
                 the DMO process.

           13. In the second NMO, inverse NMO your dataset with the same
               velocity from the first NMO.

           14. Add a Trace Display Label and Disk Data Output to label and
               output the data after the inverse NMO after DMO.

                 This output data would normally then go through velocity analysis
                 and then have NMO reapplied and stacked as the final DMO output
                 stack data volume.




Landmark                      ProMAX 3D Seismic Processing and Analysis          13-13
Chapter 13: 3D Dip Moveout


                             For this exercise, we will not be using the output data. You may elect
                             to QC the output data by running a quick flow do display a few CDP
                             ensembles.




                             Notice that all CDP’s after DMO to Gathers have the same offset
                             distribution. This poses a couple of questions:

                             •   What are the proper parameters for minimum offset, maximum
                                 offset and offset increment in the Velocity Analysis Programs?

                             •   How do you decide on a supergather for velocity analysis?
                                 Offset distribution is no longer an issue.




13-14         ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                                       Chapter 13: 3D Dip Moveout




Parallel Processing Overview

                        We have looked at few of the options for parallel processing already in
                        this class. There are actually four basic methods of parallelization:

                              •    Manual Parallel (simultaneous job submission)

                              •    Distributed (Network) Parallel using multiple ProMAX systems

                              •    SMP parallel

                              •    Massive Parallel (multi SMP)

                        We have been using the Manual Parallel approach in all of the stack jobs
                        that we have run. The following table helps summarize the types of
                        parallelization that exist in ProMAX 3D.

                  Parallel Processing Options and Availability
               Manual             Distributed      Distributed    SMP (Shared      Massive SMP
               Simultaneous       Using Parallel   within the menumemory /         (multi-SMP
                                  Begin and End                   threaded)        machines)

Executive         OK                  OK
Processes



Stack 3D          OK                  OK                              OK                 OK
DMO 3D

Migrations                                             OK
FK and PS

Migrations                                             OK             OK
FD and PSPC

Mixing Panel
Tools



                        The Parallel Executive (PVM) allows you to run most ProMAX tools in
                        parallel, the exception being mixing panel tools (i.e. Trace Mixing, 3D
                        Mix, and other tools that require a trace to be in two places at the same
                        time).




Landmark                                     ProMAX 3D Seismic Processing and Analysis        13-15
Chapter 13: 3D Dip Moveout


                             A distributed,or networked parallel session is a heterogeneous network,
                             such as SGI, SUN, IBM, appearing as a single concurrent computational
                             resource.

                             Typically when you classify parallel processing there are three types:

                             •   PVM Parallel:

                                 This mode begins with a Parallel Begin and ends with a Parallel End.
                                 The tools in-between are run concurrently on the defined hosts.
                                 Multiple Parallel Begin and Ends can be nested if required. The
                                 output data from all of the different “execs” running on the various
                                 machines are brought back together to the master ProMAX flow on
                                 the master machine.

                             •   Threaded (or SMP) Parallel:

                                 This mode may be run on machines that support the Shared Memory
                                 architecture. Typically these machines have multiple “nodes” or
                                 CP’s that all use the same memory. There are tremendous
                                 performance advantages to these machines. Currently only the 3D
                                 Stack, 3D DMO and 3D Migration programs fully utilize the SMP
                                 architecture.

                             •   Massive Parallel

                                 This generally refers to running more than one multi node SMP
                                 machine simultaneously in the same job. Currently only the 3D
                                 Stack and 3D DMO programs support massive parallelism.

                             For the PVM (Parallel Begin/End) path there are two methods of
                             distributing the work amongst the selected machines. These are Round
                             Robin and First-Come-First-Serve. The round-robin allocation to
                             distribute work guarantees that the sort order is preserved. However, the
                             round-robin allocation strategy may not be optimal for heterogeneous
                             environments with a mix of machine speeds, or machines being utilized
                             by other processes, since faster machines will tend to wait for slower
                             ones to catch up. The first-come-first-served strategy allocates work on
                             a request basis. Faster machines generate more requests than slower
                             ones, and will remain busy until the task is finished. The first-come-
                             first-served strategy does not guarantee that the primary sort order will
                             be maintained. If it is important that the primary sort order be
                             maintained in a parallel job, a good strategy is to place an Inline Sort
                             after a parallel sequence using the first-come-first-served policy.




13-16         ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                                  Chapter 13: 3D Dip Moveout




System Administration for Parallel Processing

      PVM Daemon (Parallel Virtual Machine)
                    A PVM daemon process called “pvmd” is initiated on all machines
                    participating in parallel execution. The daemons provide a network for
                    interprocess communication via message passing. The ProMAX
                    super_exec initiates a pvmd on the local machine whenever a job is
                    executed. Jobs which may not employ PVM for interprocess
                    communication will disregard the daemon’s existence, and will run on
                    the local host machine.

                    ProMAX expects the local pvmd executable to reside in the file
                    $PROMAX_HOME/sys/exe/pvmd, while the locations of the remote
                    pvmd executables are specified in the PVM host definition file
                    ($PROMAX_HOME/etc/pvhmosts), as explained below. You can
                    override the location of the local pvmd executable by specifying the
                    environment variable PROMAX_SYS_EXE_PVMD_HOME, although
                    this will generally not be required.


      User environment
                    In order to use the Parallel Executive on remote hosts, you must have
                    trusted login privileges on all nodes of the virtual machine. Trusted
                    status can be enabled system wide by modifying the /etc/hosts.equiv
                    file, or on an individual basis by adding the relevant entries to your
                    .rhosts file. You can verify trusted status by attempting to rlogin to a
                    remote host. If you do not need to supply a password, you have trusted
                    status. An alternate test is to check whether “rsh [hostname] date”
                    returns the date string without requiring other input, or without echoing
                    other strings.

                    Each thread of the Parallel Executive inherits all ProMAX and PVM
                    environment variables, as well as the DISPLAY environment variable,
                    from the initiating environment. The primary data area must be
                    available on all participating hosts, either through hard mounts or by
                    using automount. Only the primary storage partition must be declared in




Landmark                              ProMAX 3D Seismic Processing and Analysis        13-17
Chapter 13: 3D Dip Moveout


                             this manner, secondary storage partitions will follow the config_file
                             entries.

                              NOTE:

                              Currently, the path to the primary data area must be the same on all the parallel
                              hosts. This can be accomplished by ensuring that the mount points for primary
                              storage ($PROMAX_DATA_HOME) are the same on all the participating parallel
                              machines. If the common primary storage partition is already mounted at a different
                              location, you must provide a link to that mount point which mimics the mount point
                              on the other machines.



                             The Display environment variable need only be set if remote threads
                             will create displays that will be viewed on the local host. In this case you
                             must explicitly enable display on the local host, either by enabling all
                             hosts xhost+, or by enabling specific hosts xhost +host1 +host2, from a
                             console on the local host.




13-18         ProMAX 3D Seismic Processing and Analysis                                                Landmark
                                                            Chapter 13: 3D Dip Moveout




Using DIPVELS for Zero Dip Velocity Estimation

             In the case where the offset distribution prevents good population of
             offset bins for Dmo to Gathers 3D you may elect to use the DIPVELS
             program to estimate the zero dip RMS velocity field. The true use of
             DIPVELS is to estimate an azimuth dependent velocity based on a time
             variant local dip of the geology. Dipvels outputs a table that contains the
             time and azimuth dependent velocity information and this table can be
             converted to a standard velocity table where the output velocity is the
             zero dip component of the input table.

             You do not want to run the azimuth dependent velocity correction in
             conjunction with 3D DMO. Both of these processes are attempting to
             correct for similar effects. It is common to use the DIPVELS velocity
             analysis and application for Normal Moveout prior to Correlation
             Autostatics. and then run DMO to Gathers after residual statics
             application using a conventional velocity field for NMO prior to DMO.




Landmark                       ProMAX 3D Seismic Processing and Analysis          13-19
Chapter 13: 3D Dip Moveout


                                       Dipvels Theory




                               Azimuth Dependent Velocities



                Estimates velocity and dip from the stacking response of the data.


                Useful for obtaining correct stacking velocities for datasets which
                have considerable dip and need residual statics




                                                          dt
                                                                                   dt’




                                                    VRMS
             Stacking Velocity =
                                         (1-sin2(alpha) * cos2(theta-phi))

              alpha = dip angle -- theta=dip direction -- phi = shot-receiver azimuth
             Note: Stacking velocity is trace dependent, if the shot to receiver
                     azimuth varies within a CDP gather.




13-20         ProMAX 3D Seismic Processing and Analysis                       Landmark
                                                             Chapter 13: 3D Dip Moveout


                        Dipvels Bin Centering Correction




                     3D NMO and Bin Center Corrections

                                                                trace - mid point
                                         CDP - BIN
                 Bin-Center




                         T(0,0)



                                                                  T(0,R)




           3D NMO equation
                              2         2         2 1/2
           T(X,R)=(T(0,0)+R*D) +(X/Vrms) -(X/VDMO) )

           R= {Rx,Ry} Position Vector from bin center to the trace mid point
           D= {Dx,Dy} X and Y component dip

           The NMO, DMO and bin center corrections (R*D) require
           knowledge of Vrms, Dx and Dy versus time and space



Landmark                           ProMAX 3D Seismic Processing and Analysis     13-21
Chapter 13: 3D Dip Moveout




DMO Stack 3D

                             DMO Stack 3D is a constant velocity DMO process that accumulates
                             the DMO response of each trace in a stack indexed by CDP, inline, and
                             crossline location. Like DMO to Gathers 3D, this process uses an
                             Integral (Kirchhoff) method, with care taken to avoid spatial aliasing of
                             the DMO operator. Unlike DMO to Gathers 3D, DMO Stack 3D stacks
                             all offsets into a zero-offset stack trace.

                             To compensate for variations in coverage, the process maintains time-
                             dependent fold information for each stack trace, and scales each stack
                             trace by that fold. The fold information is maintained in the stack trace
                             headers and can be accessed by other processes.

                             We will also combine the preparation and DMO in a single flow.

                             If the DMO was to be run in parallel on an SMP type machine you may
                             want to also parallelize the pre-processing as well. If the preprocessing
                             is not parallelized, the DMO may not run efficiently because it will be
                             waiting for traces to come down the “pipe”. Parallelizing the
                             preprocessing may help the “pipe” keep up DMO’s demand for traces.
                             This is something may should be tested.

                             The alternative would be to run the preprocessing in a separate flow and
                             output a new prestack dataset. This dataset would then be read into the
                             DMO flow.

                             You will run this exercise differently relative to the stack flows that have
                             been run previously. In this case you will run two flows but with slight
                             parameterization changes to demonstrate a point.

                             You will run the DMO to Stack 3D to generate a fully resolved output
                             volume. The parameterization comparison will involve examining the
                             difference between rekilling and remuting vs. rekill and remute. The
                             reason for this comparison is to help demonstrate the procedures
                             involved in the cases where partially resolved data volumes are
                             generated and then merged.




13-22         ProMAX 3D Seismic Processing and Analysis                                        Landmark
                                                            Chapter 13: 3D Dip Moveout


           1. Build the following flow by copying your residual statics stack flow
              for the first half of the data as a starting point:

           Editing Flow: 45-DMO stack (rekill yes)

           Add            Delete          Execute           View         Exit

           Disk Data Input
                 Select dataset ----------------------------- shots - refr stat (1st)
                 Trace read option -------------------------------------------- Get All
           Disk Data Insert
                 Select dataset ---------------------------- shots - refr stat (2nd)
                 Trace read option -------------------------------------------- Get All
           Apply Residual Statics
                 Normal database entry naming mode?------------------- No
                 Source residual static ---------- SIN STATICS SGEMFX01
                 Receiver residual static ------- SRF STATICS SGEMFX01
           Normal Moveout Correction
                 Direction for NMO application -------------------- FORWARD
                 Stretch mute percentage ----------------------------------------- 0.
                 Apply any remaining static during NMO?----------------Yes
                 SELECT Velocity parameter file ----- after resids b4 dmo
           Trace Muting
                 SELECT mute parameter file ----- post nmo mute (brute)
           Automatic Gain Control
           DMO Stack 3D
           Trace Display Label
           Disk Data Output

           2. In Disk Data Input, input your shot-organized data with refraction
              statics applied for the first half.

           3. In the Disk Data Insert input the shot organized data with refraction
              statics for the second half.

           4. Apply the residual statics that were generated by the Gauss-Seidel
              External Model Decomposition process.

                 These are the SGEMFX01 values for the shots and receivers.




Landmark                      ProMAX 3D Seismic Processing and Analysis           13-23
Chapter 13: 3D Dip Moveout


                             5. In Normal Moveout Correction, enter the best, current RMS
                                velocity field.

                                Here we would normally use the velocities that were picked using
                                the data that was output from the Dmo to Gathers 3D process. We
                                did not run these velocities so you can use one of the other tables.

                             6. Apply the post-NMO mute.

                             7. The flow as described shows an Automatic Gain Control, you can
                                toggle this process active.

                                The output from the Stack DMO process is more aesthetically
                                appealing (on this dataset) if you apply an AGC, or other scaling
                                function, prior to the DMO process, although it is not required.

                             8. Select DMO Stack 3D parameters.

                                Host name refers to the name of the nodes where you would like to
                                run the program. This program is set up to run in parallel (on more
                                than one machine). If no host name is specified, the process executes
                                on the same host as the ProMAX executive.

                             9. Leave the restart parameter defaulted to No.

                                The restart parameter allows you to alter an existing 3D DMO stack
                                with the DMO stack response from another prestack dataset.

                             10. Specify your minimum and maximum inline and crossline numbers
                                 to include the entire dataset.

                             11. Set the CDP spacing to 55 ft.

                             12. Set the estimated maximum offset to 4500 ft., and the mute time at
                                 the largest offset to 1000 ms.

                                The estimated maximum offset parameter and the typical mute time
                                at largest offset parameter are used to determine the number of time
                                shifts required in the DMO operator

                                A shallow velocity of 9000 ft./sec is satisfactory.

                             13. Set the exponent of fold normalization scalers to 0.5.

                                The exponent of fold normalization scalers will divide each stack
                                trace by the fold normalization scaler to this power. A value of 0.5 is


13-24         ProMAX 3D Seismic Processing and Analysis                                      Landmark
                                                         Chapter 13: 3D Dip Moveout


                 recommended for noisy data, while 1.0 is recommended for
                 synthetic data.

           Editing Flow: 45-DMO stack (rekill yes) (cont)

           Add           Delete          Execute          View        Exit

           Disk Data Input
           Disk Data Insert
           Apply Residual Statics
           Normal Moveout Correction
           Trace Muting
           Automatic Gain Control
           DMO Stack 3D
                 Enter name of host -----------------------------
                 Operating system of host----------------- (as per instructor)
                 Restart with an existing stack? ------------------------------No
                 Minimum in-line number ------------------------------------------1
                 Maximum in-line number ----------------------------------------42
                 Minimum x-line number--------------------------------------------1
                 Maximum x-line number -----------------------------------------79
                 Typical CDP spacing in ensembles---------------------------55
                 Maximum offset to retain ------------------------------------4500
                 Typical mute time at largest offset ----------------------1000
                 Typical RMS velocity at early times ---------------------9000
                 Exponent of normalization factor -------------------------- 0.5
                 Number of normalization scalars per trace ----------- 100
                 Apply final datum statics after stack? -------------------Yes
                 Rekill dead traces and apply stack mutes -------------Yes
                 Size of input trace memory buffer (MB)---------------------- 4
                 Size of stack trace memory buffer (MB) ----------------------4
           Trace Display Label
                 Trace label ----------------------------------dmo stack rekill yes
           Disk Data Output
                 Output Dataset Filename --stack - with dmo (rekill yes)

           14. Set the number of fold normalization scalers to 100.




Landmark                      ProMAX 3D Seismic Processing and Analysis       13-25
Chapter 13: 3D Dip Moveout


                                The number of fold normalization scalars parameter controls the
                                time interval for which a record of the time-variant fold at each CDP
                                is maintained. Greater numbers for this parameter preserves relative
                                amplitudes better, but makes the program run longer. When using
                                the restart option to merge datasets together, these scalers will help
                                determine the relative weight of each dataset based on the fold of
                                that dataset.

                             15. Apply the CDP mean static (final datum static).

                             16. Set the rekill and mute apply switch to yes.

                                This is one parameter that will generally need to be tested. As a
                                general rule set this to YES especially if fully resolved output is
                                being generated. If you detect shallow amplitude anomalies you may
                                find that setting this to NO will help. When working in a partial stack
                                and stack merge sequence you will generally want to set this to NO
                                and then rekill and remute after the stack merge.

                                (To be demonstrated later in this chapter)

                             17. Set the size of memory buffers to 4 MB.

                                The size of memory buffers parameters are available to maximize
                                the efficiency of the program. Never allow stack buffer + 2*input
                                buffer to exceed half machine memory.

                                In this case, we will be running many jobs at the same tim, so we will
                                reduce the memory requirements for each job.

                             18. In Trace Display Label, label the dataset as being a stack after
                                 DMO.

                             19. In Disk Data Output, output a dataset for a stacked after DMO
                                 dataset.

                             20. Execute the flow.




13-26         ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                                   Chapter 13: 3D Dip Moveout


      Run DMO to Stack3D with the rekill switch set to NO
                     1. Copy the DMO stack flow for the first half of the data to make this
                        flow:

                    Editing Flow: 46-DMO stack (rekill no)

                    Add           Delete          Execute          View         Exit

                    Disk Data Input
                    Disk Data Insert
                    Apply Residual Statics
                    Normal Moveout Correction
                    Trace Muting
                    Automatic Gain Control
                    DMO Stack 3D
                          Rekill dead traces and apply stack mutes ---------------No
                    Trace Display Label
                          Trace label ------------------------------------dmo stack rekill no
                    Disk Data Output
                          Output Dataset Filename ----stack - with dmo (rekill no)

                     2. Change the rekill option in the DMO Stack 3D menu to NO

                     3. Change the Disk Data Output filename to your stack file after DMO
                        with the rekill option set to NO

                     4. Execute the flow.




Landmark                               ProMAX 3D Seismic Processing and Analysis        13-27
Chapter 13: 3D Dip Moveout


        Compare the two DMO Stack Volumes
                             1. This flow is a copy of the Compare Inlines flow, built earlier. You
                                may want to copy that flow to save yourself some work.

                         Editing Flow: 47- Compare dmo stacks

                         Add              Delete          Execute           View         Exit

                         Disk Data Input
                                 Select dataset ---------------- Stack - dmo stack (rekill yes)
                         Disk Data Insert
                                 Select dataset ------------------- Stack -dmo stack (rekill no)
                         Inline Sort
                                 PRIMARY sort key ---------- (ILINE_NO) 3D inline number
                                 SECONDARY sort---------------(DS_SEQNO) Input dataset
                                         sequence number
                                 TERTIARY sort key----(XLINE_NO) 3D crossline number
                                 Maximum traces per output ensemble -------------------- 79
                                 Number of traces in buffer ------------------------------------160
                                 Buffer type ----------------------------------------------------Memory
                                 Sort key which controls End-of-Ensemble-----Secondary
                         >Bandpass Filter<
                         >Automatic Gain Control<
                         Trace Display

                             2. Make sure that you turn the Bandpass Filter and AGC off.

                                These two processes honor the TLIVE and TEND headers and will
                                only process with these limits.




13-28         ProMAX 3D Seismic Processing and Analysis                                       Landmark
                                                          Chapter 13: 3D Dip Moveout




Trace Kill and Start Time Reset

             DMO will scatter trace amplitudes into areas where no amplitudes
             existed prior to DMO.

              Data moved to originally                      Trace start times
              unoccupied bins                               brought shallower




             You have a couple of options available regarding how to handle this
             issue. When the traces are output from the DMO process the TLIVE_S
             and TFULL_S header words are set to be those of the earliest values
             encountered for a trace that originated in the output bin. Given the
             scenario where you are creating “fully resolved” output, the TLIVE_S
             and TFULL_S header words should match those of a conventionally
             stacked trace. The “Rekill dead traces and reapply trace mutes” menu
             option determines whether or not the samples above TLIVE_S are
             zeroed or not. Normally, for fully resolved output you will want to set



Landmark                      ProMAX 3D Seismic Processing and Analysis         13-29
Chapter 13: 3D Dip Moveout


                             this to YES. The following diagram shows a comparison between
                             setting this option to NO and YES.




                             Notice that the TLIVE_S is identical for each dataset, but the trace
                             amplitudes are very different in time and space. The stack volume with
                             the switch set to YES will very closely resemble a conventional stack in
                             space and time.

                             In the event where partially resolved stacks are being generated by the
                             DMO process, it is advised to set the switch to NO and then reset the
                             trace amplitudes after the partial stacks are merged into a single fully
                             resolved stack volume.




13-30         ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                                Chapter 13: 3D Dip Moveout


      Reset Stack DMO Output
                   1. Build the following flow by copying the “stack merge” flow as a
                      starting point:

                   Editing Flow: 48-Reset DMO stack output

                   Add            Delete        Execute          View       Exit

                   Disk Data Input
                   Database/Header Transfer

                   Disk Data Input
                   Database/Header Transfer
                   Trace Kill/Reverse
                   Trace Muting
                   Trace Display Label
                   Disk Data Output

                   2. In the first Disk Data Input, read one of your conventional stack
                      files.

                   3. In the first Database to Header Transfer, move one header word to
                      the database.

                         Remember, we are working on stack traces; therefore, each CDP
                         number is different.

                         Write the TRC_TYPE trace header word from the alternate list of
                         header words to a new attribute in the CDP database called
                         TRC_TYPE. These are integers.

                   4. In the second Disk Data Input, input the DMO stack data volume.

                   5. In the second Database to Header Transfer, move one header word
                      from the database to the DMO stack trace headers.




Landmark                              ProMAX 3D Seismic Processing and Analysis     13-31
Chapter 13: 3D Dip Moveout


                               Write the TRC_TYPE attribute from the CDP database to a new
                               trace header word called REKILL.

                         Editing Flow: 48-Reset DMO stack output

                         Add            Delete          Execute           View         Exit

                         Disk Data Input
                               Select dataset -------------------------- Stack - resid stat (mrg
                               Trace read option -------------------------------------------- Get All
                         Database/Header Transfer
                               Direction of transfer --- Load FROM traces TO database
                               Number of parameters ---------------------------------------------1
                               First database parm ------- CDP GEOMETRY TRC_TYPE
                               First header entry ----------- TRC_TYPE (Trace type) - INT
                         Disk Data Input
                               Select dataset -------------------- Stack - with dmo (rekill no
                               Trace read option -------------------------------------------- Get All
                         Database/Header Transfer
                               Direction of transfer --- Load TO traces FROM database
                               Number of parameters ---------------------------------------------1
                               First database parm ------- CDP GEOMETRY TRC_TYPE
                               First header entry ------------------------------------------ REKILL
                         Trace Kill/Reverse
                         Trace Muting
                         Trace Display Label
                         Disk Data Output




13-32         ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                            Chapter 13: 3D Dip Moveout




           Editing Flow: 48-Reset DMO stack output

           Add            Delete           Execute           View         Exit

           Disk Data Input
           Database/Header Transfer
           Disk Data Input
           Database/Header Transfer
           Trace Kill/Reverse
                 Trace Editing MODE -------------------------------------------- Kill
                 Get edits from the DATABASE? ------------------------------ No
                 PRIMARY edit list header word ----------------------- REKILL
                 SECONDARY edit list header word ------------------- NONE
                 SPECIFY traces to be edited -------------------------------------2
           Trace Muting
                 Re-apply previous mutes ------------------------------ Re-ramp
           Trace Display Label
                 Trace label ---------------------------------------dmo stack (reset)
           Disk Data Output
           Output Dataset Filename-----------------stack dmo stack (reset)

           6. In Trace Kill/Reverse, kill all traces with a header word REKILL of
              2.

           7. In Trace Muting, use the TLIVE_S and TFULL_S header words to
              RE-RAMP.

                 This option re-mutes a trace to the specified time in TLIVE_S. This
                 value is reset to the value of an ordinary stack with the transfer from
                 the database.

           8. In Trace Display Label, label your dataset.

           9. In Disk Data Output, output your dataset.

           10. Execute the flow.

                 When complete, you have a new stack volume to compare with
                 previous volumes using the display comparison flows that were built
                 earlier.


Landmark                       ProMAX 3D Seismic Processing and Analysis          13-33
Chapter 13: 3D Dip Moveout




13-34         ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                          Chapter 14
                             CDP Taper on Stack Data
CDP Taper is a post stack, premigration, amplitude tapering tool that modifies the seismic data
amplitudes and stores the scalar values in the CDP GEOMETRY Ordered Parameter Files as the
TOPTAPER and BOTTAPER parameters. The top and bottom taper numbers define an amplitude
ramp that is applied to each trace in the flow.




Topics covered in this chapter:

                         t CDP Taper Overview
                         t Execution of CDP Taper
                         t Generating QC Plots of the Taper Values




Landmark                                   ProMAX 3D Seismic Processing and Analysis      14-1
Chapter 14: CDP Taper on Stack Data




CDP Taper Overview

                          In most cases you will want to apply some amplitude tapering to the
                          edge traces of a 3D prospect prior to 3D migration. Tapering does exist
                          in most of the migration programs, but this taper is relative to the padded
                          edges of a rectangularized survey. In cases where the line ends are not
                          constant you may still end up with amplitude discontinuities from line
                          to line or crossline to crossline. The CDP Taper program computes a
                          smoother amplitude scaler for the edge traces based on user specified
                          search window sizes. The higher value of search window that is input,
                          the more tapering will be applied.

                          For 3D, this tool scans the CDP fold over a moving rectangular array of
                          user defined size, computing top and bottom taper numbers for the
                          center CDP in the array.




                                                  live in the corner


                                        on the edge

                                          one line in from the edge

                                                      dead in the
                                                      corner


                                                       first live, but
                                                       not on the edge


                                              CDP Taper Example Locations


14-2          ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                       Chapter 14: CDP Taper on Stack Data




                 If there are no zero fold CDPs in the array, the taper value is 1.

                 If there are zero fold CDPs in the array and the center CDP has non-zero
                 fold, the taper number is calculated as:



           Using Equation        INT(array area/2) - number of zero fold CDPs
                                 INT(array area/2).
                                 Center CDP is on the edge
                                 (first/last line or first/last xline)
                                 Taper value = 0
                                 If CDP not on the edge then
                                 Total number of CDP’s in window = 25
                                 Total number of zero fold CDP’s = 10
                                 Taper value = (12-10)/12 = 0.17

                                 Center CDP has fold >0
                                 Total number of CDP’s in window = 25
                                 Total number of zero fold CDP’s = 5
                                 Taper value = (12-5)/12 = 0.58



                                 Center CDP has fold = 0
                                 Taper Value = 0




                                 Center CDP has fold > 0
                                 Total number of CDP’s in window = 25
                                 Total number of zero fold CDP’s = 6
                                 Taper Value = (12-6)/12 = 0.50


                                     Examples of Taper Calculation

                 If the center CDP is on a dataset edge, the fold of the center CDP is zero,
                 or the number of zero fold CDPs is greater than half the array area, the
                 taper number is 0.




Landmark                           ProMAX 3D Seismic Processing and Analysis           14-3
Chapter 14: CDP Taper on Stack Data




CDP Taper flow

                          In this exercise, we will build a CDP Taper flow and apply the tapers to
                          the stack data and QC the results on the traces and in the database.

                          1. Build the following flow:


                         Editing Flow: 49-CDP taper

                         Add            Delete          Execute           View         Exit

                         Disk Data Input
                               Select dataset -----------------------stack - dmo stack (reset)
                               Trace read option -------------------------------------------- Get All
                         CDP Taper
                               Top number of inline CDP’s ------------------------------------- 5
                               Top number of cross line CDP’s---------------------------------5
                               Bottom number of inline CDP’s----------------------------------9
                               Bottom number of cross line CDP’s----------------------------9
                         Trace Display Label
                               Trace label --------------------------------------dmo stack (taper)
                         Disk Data Output
                               Output Dataset Filename--------stack - dmo stack (taper)

                          2. In Disk Data Input, input a previously created file that is a stack
                             data set.

                               This should be the reset DMO stack.

                          3. The CDP Taper process has 4 parameters.

                               In this example we will use a 5 x 5 CDP operator at time zero and a
                               9 x 9 CDP operator at the maximum time of the input data.

                          4. Output a new stack file using Disk Data Output.

                          5. Execute the flow.

                          6. Look at the output data file compared to the input using the
                             compare inlines flow that we already have available.



14-4          ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                       Chapter 14: CDP Taper on Stack Data


               Make sure that you turn off the AGC or you will remove the effect
               of the taper.

               You will also want to set the trace scaling in Trace Display to Entire
               Screen instead of Individual since the individual scaling will also
               partially remove the effects of the tapering.

           7. With these parameters it will be difficult to see much difference
              since we essentially have a two trace taper shallow and a 4 trace
              taper at maximum time.

            NOTE:

            Notice that the first and last lines are completely dead after the CDP Taper. This is
            the expected behavior. Therefore, you may elect to pad the CDP grid by one CDP
            in all directions since CDP Taper will kill any trace on the first and last inline and
            cross line of the project.




Landmark                        ProMAX 3D Seismic Processing and Analysis                    14-5
Chapter 14: CDP Taper on Stack Data




Generating QC Plots of the Taper Values

                          The CDP Taper process writes two sets of numbers to the CDP database.
                          A single value is output for the top taper value for each CDP and for the
                          Bottom taper. We can use the database display tools to visualize how the
                          taper varies in space.


       QC Plots from XDB
                          1. Open XDB database display.

                          2. Select your area, line, and the CDP order.

                          3. Display an XYgraph of CDP: X, Y, FOLD.

                          4. Display an XYgraph of CDP: X, Y, TOPTAPER.

                          5. Display an XYgraph of CDP: X, Y, BOTTAPER.

                          6. Edit the Colorbar.

                             Set the interpolation mode to “MANUAL” and the change the color
                             of the first color box to black.

                             Here you can clearly see the original zero fold CDP’s in the fold plot
                             and you can see the traces which have been assigned a taper scaler
                             of zero.


       Try other values for TOPTAPER and BOTTAPER
                          Rerun the flow using values like 11 and 21 for the top and bottom tapers
                          and regenerate the QC plots.




14-6          ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                                              Chapter 15
                              3D Velocity Viewer/Editor
This stand-alone tool allows you to scan through a 3D velocity field, identify and edit velocity
control points, and analyze the interpolation between the control points. This tool also lets you
smooth the velocity field and convert stacking velocities to interval velocities.

Typically, the tool is used to analyze velocities for anomalous points that you may want to edit. In
particular, bad velocities are frequently created when converting stacking velocities to interval
velocities. This tool ensures that a reasonable velocity field is being passed to a migration.




Topics covered in this chapter:

                           t 3D Velocity Viewer/Editor Overview
                           t 3D Velocity Viewer/Editor flow




Landmark                                     ProMAX 3D Seismic Processing and Analysis          15-1
Chapter 15: 3D Velocity Viewer/Editor




3D Velocity Viewer/Editor Overview

                                The following figures are included to you use the tool.

                                    Inline view of velocity field
                       Pulldown menus                                   Last crossline location
                                    Locations of velocity functions
                                    near the viewing plane

                                                        Last time slice location




        Icon Bar
                            •   Zoom: Enables zooming of the velocity field.




                            •   Move: Move view forward and back or up and down. Also used to
                                flip to an inline view when in a crossline view and visa-versa.


15-2           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                           Chapter 15: 3D Velocity Viewer/Editor




                     •   Rotate: Rotate to an inline, crossline, or time slice view.



                     •   Edit vel function: Popup another screen to display and edit a
                         selected velocity function.



                     •   Display Vel Scale: Display a simple velocity scale.



                                   Time Slice View




                     Circles represent location of the velocity functions. Black lines indicates
                     triangulation for spatial interpolation of velocity functions. Solid white
                     lines mark last displayed inline and crossline views. Dashed white lines
                     mark width of zone used to mark nearby velocity functions on the axis
                     of an inline or crossline view.


      3D Table Triangulation
                     The above time slice view shows the triangulation used for spatial
                     interpolation by ProMAX tables. After values in a table are interpolated


Landmark                               ProMAX 3D Seismic Processing and Analysis           15-3
Chapter 15: 3D Velocity Viewer/Editor


                            vertically in time or depth, they are interpolated spatially using the 3
                            vertexes of the triangle that encloses the location to interpolate. The
                            triangulation of the function locations is defined via the Delaunay
                            approach that produces the most equilateral triangles possible.




15-4           ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                           Chapter 15: 3D Velocity Viewer/Editor




3D Velocity Viewer/Editor flow

                     This exercise illustrates parameter selection and execution of the 3D
                     Velocity Viewer/Editor. We will input one of the RMS stacking fields
                     and output two new velocity tables: one for FK migration and another
                     interval velocity field for Phase Shift migration.


      Select the 3D Velocity Viewer Parameters
                     1. Build the following flow:

                    Editing Flow: 50-Vel condition for mig

                    Add            Delete          Execute          View         Exit

                    3D Velocity Viewer/Editor*
                          Select the type of field to edit --------- Stacking (RMS) vel
                          Do you wish to edit an existing table -------------------- yes
                          Select input velocity----------------------------------- “best vels”
                          Do you wish to specify the bounds of the field?------- No
                          Select output velocity database ---- smoothed for fk mig
                          Specify and alternative name of output INTV --------- Yes
                          Select output Interval velocity -------- for phase shift mig
                          Minimum depth (or time) -------------------------------------------0
                          Maximum depth (or time) ------------------------------------------0

                     2. Input one of the RMS velocity fields that are available.

                          If you did not complete the velocity field picking you may use the
                          original field that we imported from the ASCII file.

                     3. Specify an output name for the edited RMS field.

                     4. Enter an new name for the output interval velocity table.

                          We will output two tables from this program. One edited and
                          smoothed in preparation for FK Migration and another that is an
                          Interval Velocity as a function of time for phase Shift 3D Migration.

                     5. Execute the flow.


Landmark                                ProMAX 3D Seismic Processing and Analysis          15-5
Chapter 15: 3D Velocity Viewer/Editor


        Edit and Smooth the RMS Velocity for FK Migration
                            1. Click on the Edit Icon and move the cursor into the display area.

                                The screen will adjust to have two windows. On the left is the
                                velocity contour and on the right is the velocity function edit
                                window.

                                                Edit velocity function window




        Edit Icon




                         Location of                       Velocity function            Additional
                         velocity function                 being edited                 function
                         being edited                      (circles mark                used as
                                    Location of            control points)              reference
                                    additional
                                    velocity
                                    function used        Conversion of velocity
                                    as reference         being edited to interval velocity
                                    for plot on          (two different conversion
                                    right side.          methods are being used)


        Icon Bar

                            •   Zoom: Enables zooming of the velocity field.




15-6           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                             Chapter 15: 3D Velocity Viewer/Editor


                      •    Picking Tool: Edit velocity points




      Editing Velocities
                           The Edit velocity function window will contain the function nearest
                           to your mouse location, The right hand window shows the location
                           of the control points with blue circles. The mouse help at the bottom
                           of the screen guides your mouse motions.

                           MB1: Edits the nearest velocity function. This edit function will
                           appear in the right window in red. As you move your mouse, the blue
                           function will still reflect the function nearest to your mouse location.
                           In this way, you can compare two functions. To freeze a blue
                           function you can use MB2. Move your mouse to the right window
                           and activate the Edit Function Icon. This lets you add/move/delete
                           the red function locations marked by the circles. Use the mouse
                           button helps at the bottom of the screen as a guide.

                           MB3: Delete all points at a function location, and hence delete the
                           function.

                           Shift MB1: Adds a new function at a certain location.

                           Anther way to think of this is to Freeze the blue curve on a function
                           that you like with MB2 and edit the questionable function with
                           MB1.

                           When you press UPDATE with your new velocity function, you will
                           see its effect on the entire velocity field. If you don’t like your
                           changes, use the Modify/Undo button to remove the old function.

                      2. Move from line to line and change the display from inlines,
                         crosslines and time slices.

                           Hand edit the major discontinuities.




Landmark                                 ProMAX 3D Seismic Processing and Analysis           15-7
Chapter 15: 3D Velocity Viewer/Editor


        Velocity Field Gridding and Smoothing
                            1. Select the Modify ¦ Smooth Velocity field pull down menu to
                               smooth the RMS velocity field.




                                The first two entries ask about the sampling of the new smoothed
                                field. We can enter values that are the same as our input field.

                                •   Crossline Sampling Interval of 20
                                •   Inline Sampling Interval of 10

                            The time sampling is up to the processor and how complex the velocity
                            field is as a function of time. Our field is fairly well behaved with no
                            inversions and a relatively linear increase as a function of time. We can
                            resample our field at 200 ms intervals without any problems.

                                •   Time Sampling Interval of 200 ms

                            The smoothing parameters may also need to be modified.. Normally you
                            would measure the anomaly size (in CDPs) that you want to smooth
                            through on the inline or crossline displays and input these values. For
                            our purposes values of around 20 inline and crosslines with about 200
                            msec of smoothing should be adequate

                                •   Crossline smoothing Operator Length of 20
                                •   Inline Smoothing Operator Length of 20
                                •   Time Smoothing Operator Length of 200



15-8           ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                          Chapter 15: 3D Velocity Viewer/Editor


                      2. Click OK.

                      3. Review the smoothing operation by looking at inlines, crosslines
                         and time slices.

                      4. If the smoother was too harsh you can use the Modify ¦ Undo last
                         change pull down, reset the parameters and repeat the process until
                         satisfied.

                      5. Save this velocity field to disk using the File ¦ Save table to disk
                         pull down menu.

                         This will save the edited and smoothed RMS velocity field for FK
                         migration.


      Convert to Interval Velocity
                      1. Select the Modify ¦ Convert RMS to Interval Velocity pull down
                         menu.

                         There are two choices, Constant Velocity Dix or a Smoothed
                         Gradient Dix conversion. For our purposes in making and interval
                         velocity vs. time function we will choose the Smoothed Gradient
                         method.

                      2. Review some inlines, crosslines and time slices after the conversion
                         and see if any additional smoothing or editing is required.

                      3. Use the File ¦ Save table to disk and exit pull down menu to save
                         this table to disk and exit the program.

                         We now have two velocity fields:

                         •   A smoothed RMS field for FK migration and

                         •   A smoothed Interval Velocity field for Phase Shift 3D migration.




Landmark                               ProMAX 3D Seismic Processing and Analysis          15-9
Chapter 15: 3D Velocity Viewer/Editor




15-10          ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                             Chapter 16
                                                                       Migration
The ProMAX 3D migrations include poststack time and depth migration algorithms. The
available migrations are F-K, Finite Difference (FD), and Phase Shift. The goal is to migrate the
stack section with the most appropriate migration process. To aid in selecting the appropriate
migration, this chapter includes a comparison of the migrations and a brief description of each.
The ProMAX 3D Reference manual and the online help system also provide additional detail
about the migrations.




Topics covered in this chapter:

                          t 3D Migration Summary
                          t 3D Migration flow




Landmark                                    ProMAX 3D Seismic Processing and Analysis         16-1
Chapter 16: Migration




3D Migration Summary

                          The choice of poststack migration process can be difficult. You must
                          weigh CPU time, accuracy of the velocity model, steepness of dip to be
                          imaged, and other factors in choosing the most appropriate process.
                          Often, a number of different migrations must be run in order to compare
                          results. To help you decide on the optimal migration for a given
                          situation, the migrations are summarized.

                                                                                          Rel.
   Migration Name        Type         Domain Velocity          V(x,y) V(t/z)     Dip
                                                                                          Time

   Stolt 3D              F-K          Time       VRMS(x,y,t) Poor      Poor      Fair     0.9
   Phase Shift 3D        Phase Shift Time        VINT(t)       Poor    Good      Excel    1
   Explicit FD 3D Time F-X            Time       VINT(x,y,t) Fair      Excel     Good     13
   Explicit FD 3D Depth F-X           Depth      VINT(x,y,z) Good      Excel     Good     18
   PSPC 3D Depth         Phase Shift Depth       VINT(x,y,z) Good      Good      Excel    5

                          Some of the 3D migrations provide two important restart options. The
                          first option is activated by choosing to checkpoint the process, which
                          will regularly save migration workfiles to disk. In the case that your
                          migration process is abnormally terminated, the migration can be
                          restarted from the last checkpoint. The second option is activated by
                          choosing to save data at a specific depth for restart. In this case, data
                          may be migrated down through the current, reliable velocity information
                          and then subsequently be continued with new velocity information
                          below.

                          Data input to these migrations must be corrected to a flat datum. If your
                          data is referenced to a floating datum, you will need to complete the
                          application of datum statics to move your data to a flat datum. If your
                          velocity field is referenced to a floating datum, you can modify the
                          velocity field with Velocity Manipulation.

                          Also, the stacked data must be sorted with the primary sort of inline and
                          the secondary sort of crossline. Use the Pad 3d Stack Volume process to
                          pad the stacked data using ILINE_NO as the primary sort. The padded
                          traces should be sorted with the primary sort of inline and the secondary
                          sort of crossline.




16-2           ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                                          Chapter 16: Migration


                     With all 3D Migrations, you should be aware of the potential need for
                     extended scratch space. How much scratch space a particular migration
                     will use may be determined in the View file. When running 3D
                     Migrations in parallel, certain conventions should be followed for
                     naming scratch space on these machines. Refer to the Extended Scratch
                     Space section in the System Administration manual for a complete
                     description of the extended scratch space setup and requirements.


      Stolt 3D Migration
                     Stolt migration is computationally efficient, but has difficulty imaging
                     steep dips in areas where there are large horizontal and vertical velocity
                     variations. This algorithm uses Stolt’s (1978) stretching technique to
                     account for horizontal and vertical velocity variations. The F-K process
                     requires RMS velocities as input and migrates common offset or stacked
                     data. It is our fastest migration algorithm. Velocity variations are
                     compensated for via the Stolt stretch. This algorithm does not accurately
                     handle strong vertical or horizontal velocity variations.


      Phase Shift Migration
                     The Phase Shift migration process uses an interval velocity vs. time
                     field. It can migrate dips greater than 90 degrees (turning rays) and,
                     unlike the 2D equivalent, this 3D migration can handle lateral velocity
                     variations to a limited extent utilizing a modified stretching technique.
                     The primary advantages of this approach are speed and accurate
                     handling of high dips.


      PSPC 3D Depth Migration
                     The PSPC Depth migration process uses a spatially-variant interval
                     velocity function in time, VINT(x,y,t). Vertical velocity variations are
                     handled very well by this algorithm. Spatial velocity variations are
                     accommodated with a first-order phase correction, applied to phase-
                     shift migrated data. A phase-shift interpolation option is included for
                     increased accuracy. With this option, the first-order phase correction is
                     applied to the migrated data corresponding to the closest approximation
                     to the required velocity value. The primary advantages of this approach
                     are relative speed, accurate handling of high dips, and good
                     compensation for spatial velocity variations.




Landmark                               ProMAX 3D Seismic Processing and Analysis          16-3
Chapter 16: Migration


        Explicit FD 3D Time Migration
                          This algorithm uses explicit F-XY spatially-variant extrapolators to
                          perform time migration. This migration is designed to be accurate up to
                          approximately 70 degrees of dip. This migration uses a vertical and
                          spatially-variant interval velocity field in time, VINT(x,y,t), for input.

                          To reduce run times for this algorithm you may specify a maximum dip
                          of either 30 or 50 degrees, rather than the default of 70 degrees. Run
                          times are dependent upon the maximum frequency for migration, so
                          choose this value accordingly. A further option to enhance performance
                          is to select the Split option, for two-pass migration, instead of the Full
                          3D option, for one-pass migration.


        Explicit FD 3D Depth Migration
                          This is an algorithm which uses explicit F-XY spatially-variant
                          extrapolators to perform 3D depth migration. This migration is designed
                          to be accurate up to approximately 70 degrees of dip. This migration
                          uses a vertical and spatially-variant interval velocity field in depth,
                          VINT(x,y,z), for input.

                          You can choose from 30, 50, and 70 degree options of which the higher
                          maximum dip angles have longer run times. A further option to enhance
                          performance is to select the Split option, for two-pass migration, over
                          the Full 3D option, for one-pass migration. The primary advantages of
                          this approach are efficiency and good handling of vertically-variant
                          velocities and moderate dips, and fair handling of spatial velocity
                          variations. Trace padding should be specified to reduce wrap-around
                          effects in the frequency domain. Values in the range of 30 to 50 percent
                          are generally adequate for normal amplitude-balanced datasets.

                          Explicit FD 3D migration requires that the trace spacing of the input
                          data is equal in the inline and crossline directions. If this is not the case
                          in your 3D survey, use one of the trace interpolation techniques
                          available in ProMAX. Create a new line and run 3D Poststack Geometry
                          on the interpolated dataset to create a CDP database and have the
                          appropriate trace spacings entered in the LIN database.




16-4           ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                                 Chapter 16: Migration




Re-datum Velocities to Flat Datum

             As mentioned in the earlier discussion, you may want to adjust the start
             times of your velocity functions, which are referenced to floating datum,
             to be referenced to the flat reference datum so they match the start time
             of the stack data.

             This can be accomplished very easily using the Velocity Manipulation
             process.




Landmark                       ProMAX 3D Seismic Processing and Analysis         16-5
Chapter 16: Migration


        Re-datum the Interval Velocities
                          1. Build the following flow:


                         Editing Flow: 51- redatum velocities

                         Add           Delete         Execute          View        Exit

                         Velocity Manipulation*
                               Type of velocity table to input --- Interval Vel in Time
                               Get velocity table from database? -----------------Yes
                               Select input velocity database entry -- for phase shift
                               Combine a second velocity table with the first ---- No
                               Resample the input velocity table(s)? ---------------No
                               Shift or stretch the input velocity table?----------- No
                               Adjust the velocities to final datum ---------------- Yes
                               Type of parameter table to output --- Int Vel in Time
                               Select output velocity database entry ----------------
                               ------------------------------------- for ps mig - at datum
                               Output a single average velocity table? ------------ No
                               Vertically resample the output velocity table? ---- No
                               Adjust output velocities by percentages? ---------- No
                         3D Velocity Viewer/Editor
                               Select the type of field to edit - Interval Velocity in Time
                               Select input velocity database entry ------------------
                               ------------------------------------- for ps mig - at datum

                          You may elect to view the input and output fields using the 3D Velocity
                          Viewer/ Editor.




16-6           ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                                 Chapter 16: Migration




3D Migration Exercise

             1. Build the following flow by copying the DMO stack flow:.


            Editing Flow: 52- migration - phase shift

            Add           Delete          Execute          View        Exit

            Disk Data Input
                  Select dataset -----------stack - dmo stack (CDP Taper)
                  Trace read option ---------SORT - ILINE x XLINE *:*/
            Phase Shift 3D Migration
                  Enter name of migration server host(s) ----------
                  Number of migration server nodes----------------------1
                  Select Velocity parameter file ----- for phase shift mig
                  Minimum/maximum in-line numbers --------------1/ 42
                  Minimum/maximum x-line numbers--------------- 1/ 79
                  Maximum migrated time --------------------------------0
                  Migrated time sampling interval ---------------------- 0
                  Minimum frequency to migrate -------------------------0
                  Maximum frequency to migrate -----------------------80
                  Number of in-line traces to pad --------------------------0
                  Number of cross-line traces to pad --------------------0
                  In-line taper length (in traces) ------------------------- 0
                  Cross-line taper length (in traces) --------------------- 0
                  Top time taper (in ms) ------------------------------- 100
                  Bottom time taper (in ms) -------------------------- 100
                  Re-apply trace mutes and rekill dead traces? -----Yes
            Trace Display Label
                  Trace label -----------------------------mig - phase shift
            Disk Data Output
                  Output Dataset Filename-------migration - phase shift

             2. In Disk Data Input, input the stack dataset after DMO and CDP
                Taper.

             3. Select the Phase Shift Migration parameters.


Landmark                       ProMAX 3D Seismic Processing and Analysis         16-7
Chapter 16: Migration


                          4. Select the Interval Velocity vs. Time function that we generated
                             specifically for Phase Shift migration using the velocity editor.

                          5. Set the frequency range to start at 0 and go to 80 Hz.

                             This is a reasonable range for this dataset. You could improve the
                             performance of the migration by reducing the frequency range.

                          6. Leave the pad parameters at 0 traces.

                             Normally you would want to compute the migration aperture and
                             add enough traces to prevent the energy from wrapping from one
                             side of the stack to the other. In this case, we are just interested in
                             getting the flow to quickly run. So you can expect to see some spatial
                             wrap on the output section.

                          7. Set the top taper to 100 ms and the bottom taper to 100 ms.

                             Since you have applied the AGC prior to the Stack DMO, our dataset
                             is fairly well modulated in amplitude and you do not require long
                             tapers.

                          8. Reapply the original mutes and rekill any traces that were originally
                             dead.

                          9. In Trace Display Label, label your dataset.

                          10. In Disk Data Output, output your dataset.

                          11. Execute the flow.

                          12. When complete, you have a new stack volume. You can compare
                              this volume to previous volumes using the display comparison
                              flows that were built earlier.

                           NOTE:

                           Make sure your $PROMAX_HOME/etc/pvmhosts file is set up correctly. This is
                           the first thing to check if a migration fails to run.




16-8           ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                                                          Chapter 17
                 ProMAX Marine 3D Geometry
Geometry Assignment is designed to create the standard Ordered Parameter File directories,
OPFs, and load standard ProMAX geometry information into the trace headers. The sequence of
steps depends upon available information. This chapter serves as an example of how you would
do the geometry assignment sequence for marine 3D data. The Geometry Overview section in the
Reference Manual and online helpfile provide further details of the geometry assignment process.




Topics covered in this chapter:

                         t 3D Marine Geometry from UKOOA Data




Landmark                                   ProMAX 3D Seismic Processing and Analysis       17-1
Chapter 17: ProMAX Marine 3D Geometry




3D Marine Geometry from UKOOA Data

                         In this exercise, you will import a UKOOA file which is the standard
                         output from navigation processing. The file contains:

                         •    coordinates for each shot location

                         •    receiver coordinates for each trace of each shot.

                         You will load this single file to provide the SIN and TRC spreadsheets
                         with data. You will then continue with binning, using the Calc-Dim
                         option.

                         This marine 3D survey was collected using a single source / single cable
                         geometry.


       Using the Marine 3D Geometry Spreadsheet
                         1. Make a new line, called “3D Marine”.

                         2. Build the following flow:


                        Editing Flow: 01 - spreadsheet

                        Add             Delete         Execute          View       Exit

                        3D Marine Geometry Spreadsheet

                         1. Execute the flow.

                         2. From the global commands select File ¦ UKOOA Import




                              Enter the directory name as described by your instructor and then
                              click OK.

                         3. Choose the 3d_marine_ukooa file from the list.



17-2          ProMAX 3D Seismic Processing and Analysis                                Landmark
                                           Chapter 17: ProMAX Marine 3D Geometry




           4. From the Format pulldown menu, open a list of saved formats and
              choose STANDARD UKOOA 90 Marine 3D.

           Separate the windows.




           5. Check the column definitions by clicking on the words in the
              Parameter column.

              Notice that there are two column definitions:

              •   One for the “R” cards

              •   one for the” S” and “V” cards

              Also note that, if desired, the coordinates can be altered using the
              Math Op and Op Value columns.




Landmark                    ProMAX 3D Seismic Processing and Analysis          17-3
Chapter 17: ProMAX Marine 3D Geometry


                         6. Select Apply and then Overwrite to apply the format to all the
                            data.




                         While the import is running, you will see a variety of Status windows.
                         Eventually you will see a “Successfully Completed” window.

                         7. Quit from each of the column definition windows and select the
                            File ¦ Exit from the main import window.

                         8. From the main menu click Setup and input the following
                            information:

                         •   25 m receiver station interval

                         •   25 m source station interval

                         •   50 m sail line (crossline) interval

                         •   Set the azimuths to 0o for the shots and receivers (the correct
                             azimuth will be determined later).

                         9. Click OK.

                         10. Generate a basemap of the project by opening the Sources
                             Spreadsheet and selecting View ¦ View All ¦ Basemap.




17-4          ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                                   Chapter 17: ProMAX Marine 3D Geometry


      Determine Primary Azimuth for Binning
                    1. Use the “Double Fold” icon to measure the azimuth of the shot lines.



                                           25 mt group int
                                           25 mt shot int
                                           50 mt line spacing
                                           32 degree azimuth




                       You should measure a value of approximately 32 degrees East of
                       North.

                    2. Go back the File ¦ Setup window and enter the 32o azimuth for
                       both the shots and receivers.




Landmark                             ProMAX 3D Seismic Processing and Analysis        17-5
Chapter 17: ProMAX Marine 3D Geometry


       Cable Feather QC
                         Using the same Basemap you can generate a quick QC display showing
                         the cable feather for individual shots or for entire shot lines.

                         1. Click on the “Highlight Contributors to Trace Domain” Icon and
                            then follow the mouse button helps to display the cables for the shots




                         2. Click MB1 on any shot and its cable will highlight.

                         3. Click MB2 near a shot and all shots on the same shot line will
                            highlight.

                         4. Click Shift-MB2 to clear the screen.

                         5. Repeat as desired.

                         6. Exit from the XYGraph selecting File ¦ Exit ¦ Confirm.



17-6          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                                   Chapter 17: ProMAX Marine 3D Geometry


      CDP Binning
                    1. In the main menu, click Bin.




                    2. In the 3D Binning and QC window, select Assign midpoints by:
                       Existing index number mappings in the TRC and click OK.




                     Note:

                     You are assigning midpoints based on existing index number
                     mappings in the TRC. You loaded the x,y positions for each shot and
                     each receiver for each shot from the UKOOA file




Landmark                             ProMAX 3D Seismic Processing and Analysis       17-7
Chapter 17: ProMAX Marine 3D Geometry


                         3. Click the Binning checkbox, select Bin midpoints for Binning
                            type and click OK to open the bin definition window.




                                                   Grid Constants




                         4. Give the Grid a name and set the following grid constants:

                            Grid Azimuth = 32, dx=50, dy=12.5,



17-8          ProMAX 3D Seismic Processing and Analysis                              Landmark
                                             Chapter 17: ProMAX Marine 3D Geometry


           5. Click Calc Dim.

              A grid is automatically calculated to include all midpoints.The
              origin of the grid is computed as well as the extents of the grid
              parallel and perpendicular to the azimuth.




                                     Calculated Values

           6. Click OK to dismiss the notification window.

           7. Click Save to save the grid.




Landmark                    ProMAX 3D Seismic Processing and Analysis             17-9
Chapter 17: ProMAX Marine 3D Geometry


        QC the Calculated Grid
                         1. Select Define binning grid from the main binning window and click
                            OK.




                            This will bring up a XY Graph display window.

                         2. Select Display ¦ Midpoint ¦ Control Points ¦ Black
                            (depending on the color of the background).




17-10         ProMAX 3D Seismic Processing and Analysis                            Landmark
                                          Chapter 17: ProMAX Marine 3D Geometry


           You should get the following display:




                                Subsurface Point Scatter

           3. Select Grid ¦ Open and the grid name that you saved from the
              Calc Dim operation.




Landmark                    ProMAX 3D Seismic Processing and Analysis    17-11
Chapter 17: ProMAX Marine 3D Geometry


                            This step overlays the bin grid on your subsurface data.




                                        Overlay the Grid and the Shot Locations

                         4. You may elect to display shot locations by selecting Display ¦
                            Source ¦ Control Points ¦ White.


        Interactive Grid QC and Alteration
                         1. You may elect to alter the grid by using any of the interactive grid
                            editing icons if desired.

                            You may choose to have one subsurface line for each surface sail
                            line. In this case you may elect to turn off the midpoint and shot plots
                            and redisplay the shots only in black.

                            Views ¦ Remove ¦ Shot based Posting of Position



17-12         ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                            Chapter 17: ProMAX Marine 3D Geometry


              Views ¦ Remove ¦ Midpoint based Posting of Position

              Display ¦ Source ¦ Control Points ¦ Black

              Grid ¦ Display

           2. Next, Zoom in on an area and reposition the proposed CDP binning
              grid so that the centers of the Grids follow the sail lines and so that
              the shot locations coincide with a CDP bin centers.




                                One CDP Line per Sail Line

           3. It may help to delete one “inline” from the calculated grid and then
              adjust the inline extents by redisplaying the Midpoint Control
              Points (Display ¦ Midpoint ¦ Control Points ¦ Black).




Landmark                     ProMAX 3D Seismic Processing and Analysis         17-13
Chapter 17: ProMAX Marine 3D Geometry


                         4. You may end up with a final CDP bin Grid similar to that shown in
                            the following diagram:




                         5. When satisfied with the CDP Grid make sure that you save it before
                            exiting from the XYgraph. Select Grid ¦ Save to and enter a new
                            grid name in the dialog box and click OK:




17-14         ProMAX 3D Seismic Processing and Analysis                             Landmark
                                                    Chapter 17: ProMAX Marine 3D Geometry


                     6. Exit from the XYGraph using File ¦ Exit ¦ Confirm.


      Load Final Grid and Perform CDP Binning
                     1. Return to the 3D Marine Midpoint Binning Window and click Load
                        to apply the final grid parameters to this menu.




                      2




                                                                  3




                      1




                     2. Select the bin space name that was saved in the XYgraph session

                     3. Click OK.


      Critical Parameters During CDP Binning
                     Even if you know that you are going to run the Flex Binning processes
                     prior to Velocity Analysis, Stack, DMO and Migration, it is very
                     important to get the conventional CDP binning and Offset Binning
                     Parameters correct.



Landmark                              ProMAX 3D Seismic Processing and Analysis      17-15
Chapter 17: ProMAX Marine 3D Geometry


                         The CDP Binning parameters, even after Flex Binning, still control how
                         many lines and cross lines exist for the project. The often overlooked
                         parameters pertaining to offset binning are extremely important in the
                         case of Flex Binning.

                         In the Flex Binning assignment one of the most critical parameters
                         pertains to the number of traces per offset bin that should contribute to
                         each CDP. Typically, this will be set to 1 in order to stabilize the offset
                         contribution to each CDP. If the original offset binning is not done
                         correctly, then there is no way to stabilize the Flex Binning output.

                         The goal of the Offset Binning is to achieve one trace per CDP per offset
                         bin, the same requirement as for DMO processing. For a typical marine
                         case you would specify the offset bin increment as twice the shot
                         interval. In this case the shot interval and the group interval are the same
                         at 25 meters which means an offset bin width of 50 meters.

                                                     25 mt group intv
                         3182 mt
                                                                        x
                                               near offset = 207
                                               next offset = 232
                                                                  207 mt
                     maximum offset = 3182 mt
                                                        first bin center = 219.5
                                                        minimum offset to bin = 194.5
                                                        maximum offset to bin > 3219.5
                                                        offset bin increment = 50


                                                       50 mt offset bin intv
                        3182 mt

                                                                        x
                                   first bin center = 219.5
                                 minimum offset to bin = 194.5
                     maximum offset to bin > 3219.5
                     use 3300 ft                   offset bin increment = 50




17-16         ProMAX 3D Seismic Processing and Analysis                                    Landmark
                                            Chapter 17: ProMAX Marine 3D Geometry




                                                                    219.5




                         CDP Binning Parameters for Marine 3D

           In this case we will use offset bins that have bin centers at 50 meter
           increments with a near offset bin center at 219.5 meters and a far offset
           of 3300 meters.

           You can use a display from the database to QC these parameters after
           the final binning step. If you plot a 3D: XYgraph, from the TRC order
           and plot OFFSET in X, CDP in Y and color code by OFB, you can see
           the offset distributions on the CDP gathers. After some selective
           zooming you can overlay the proposed offset binning grid for QC. You
           may also find that using the “contrast.rgb” color table in the
           $PROMAX_HOME/port/misc directory will be useful.




Landmark                     ProMAX 3D Seismic Processing and Analysis        17-17
Chapter 17: ProMAX Marine 3D Geometry




                                Zoom of Offset vs CDP plot with Offset Bins Overlay

                         You will also notice on this plot that in areas there are duplicate offsets
                         at given CDPs thus making it impossible to reach the goal of 1 trace per
                         CDP per bin.

                         4. Make sure that Inlines parallel to grid Y axis is selected.

                         5. Click Apply.


17-18         ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                                       Chapter 17: ProMAX Marine 3D Geometry


                         After the Binning is complete, click Cancel on the 3D Marine
                         Midpoint Binning window.


      Receiver Binning
                         This step is optional. It is only required if you intend to run surface
                         consistent processing such as surface consistent deconvolution or
                         residual statics.

                    1. Click the checkbox for Binning, select Bin the receivers and click
                       OK.


                                                                            3
                     1
                                                             5          4

                                                                    2



                                                                                6




                    2. Load the information from the CDP grid as a starting point.

                    3. Change the Y dimension of the receiver grid to match the group
                       interval of 25 meters.

                    4. Enter a name for the Bin space such as receiver grid 32 degrees 50
                       by 25.

                    5. Automatically compute the extents of the receiver grid by clicking
                       Calc Dim.

                    6. Perform the binning by clicking Apply.

                         A Binning receiver locations.... window appears.

                    7. Select Cancel on the 3D Marine Receiver Binning window when
                       the binning is complete.




Landmark                               ProMAX 3D Seismic Processing and Analysis          17-19
Chapter 17: ProMAX Marine 3D Geometry


        QC the CDP Binned Data using a Fold Plot
                         1. Select QC Midpoint Bin data, Coordinate Space Fold display,
                            then select your bin grid from QC Bin Space list and click OK.




        Finalize the Database
                         1. Select Finalize Database, and click OK.




                         2. When complete, click Cancel on the 3D Binning and QC window.

                         3. Exit the Spreadsheet window by selecting File ¦ Exit.



17-20         ProMAX 3D Seismic Processing and Analysis                             Landmark
                                                         Chapter 17: ProMAX Marine 3D Geometry




Assigning CDP Flex Binning

                     1. Build the following flow:


                    Editing Flow: Assign CDP flex binning

                    Add            Delete            Execute            View         Exit

                    Assign CDP Flex Binning*
                          Crossline overlap factor ------------------------------------------- 3
                          Inline overlap factor -------------------------------------------------1
                          Maximum number of trace/offset bin-------------------------1
                          Omit traces with zero weight --------------------------------- No
                          Limit flex binning to subset of survey --------------------- No
                          Apply crossline distance weighting ----------------------- Yes
                          Crossline distance weighting ------------------------------
                          ---------------------------------------------0: 0-1, 52-0/3000: 0-1, 75-0/
                          Apply inline distance weighting ---------------------------- Yes
                          Inline distance weighting --------------------------0: 0-1, 6.25-0
                          Apply azimuth weighting rule -------------------------------- No
                          Apply prime line weighting ----------------------------------- Yes
                          Prime line weighting ------------- 0:1.0,0.1/3000:1.0,0.8/
                          Number of user defined rules ----------------------------- None
                          Verbose printout? -------------------------------------------------- No

                     2. Let us look at the parameters for the Assign Flex Binning Process
                        in greater detail.


      Inline and Crossline Overlap Factors
                          The Inline and Crossline overlap factors define the total search radii
                          for all traces that may contribute to an output CDP.

                          The input values are in numbers of original CDP bins.




Landmark                                ProMAX 3D Seismic Processing and Analysis              17-21
Chapter 17: ProMAX Marine 3D Geometry




                                                                           Crossline Overlap Factor = 2.0
                             Crossline Direction




                                                                   Inline Overlap Factor = 0.8


                                                           Inline Direction

                                                   Inline and Crossline Overlap Factors

                            Typical values for these parameters would be 1 in the inline direction
                            and somewhere between 2 and 5 in the crossline direction. For our
                            case we will run with 3 in the crossline direction which means that
                            we will search the current line and 1 line on each side for
                            contributors.

                         3. We will allow 1 trace per offset bin.

                         4. Allow traces with zero weight to contribute.

                            This means that if, for some reason, the only trace that is available
                            for a particular offset bin in a CDP has a weight of zero, use it
                            anyway.

                         5. Do NOT limit the Flex Binning to a subset of the survey.

                            Process the entire project.




17-22         ProMAX 3D Seismic Processing and Analysis                                                     Landmark
                                                           Chapter 17: ProMAX Marine 3D Geometry


      Inline and Crossline distance Weighting
                          6. Parameterize the Crossline and Inline weighting.

                               Typically, these weighting functions will be offset variant. We will
                               generally want to keep the near traces from the original stack track
                               but we will generally need to change the weight function parameters
                               for the far offsets.




            Inline Overlap = 1                                     Inline Bin Size=12.5
            Crossline Overlap=3                                    Cross Line Bin Size=50

                     Near                                             Far
                     Offsets                                          Offsets


                                       1                                                 1
                                                                                          inline
                                                                                         direction
                                     53’

                                 0                                                    75’
                                                                                  0
                 1
                                                                    1
           XLine --> offset: distance - weights
                0: 0-1, 53-0                                          3000: 0-1, 75-0
           Inline --> offset: distance - weights
                0: 0-1, 6.25-0

                                           Inline and Xline Distance Weighting


      Azimuth Weighting
                          7. Parameterize the Azimuth weighting.

                               Again you may elect to vary the azimuth weights as a function of
                               offset where you would weight the traces with the prime sail line



Landmark                                     ProMAX 3D Seismic Processing and Analysis       17-23
Chapter 17: ProMAX Marine 3D Geometry


                            azimuth higher than others. You may find that you will have to open
                            the weight range for the far offsets where feathering is greater.




                                                                                   Pass Azimuth 1




                                                                                          Pass Azimuth 2
                                                                                        Taper Length




                             Pass weight          Linearly tapered weight          Reject weight

                             Pass weight if Reciprocal Traces = ‘Yes’, otherwise reject weight

                             Lineraly tapered weight if Reciprocal Traces = ‘Yes’, otherwise reject weight



                                                Azimuth Weighting Schematic

                            for our example you may use 3 different weighting schemes for
                            different offset, azimuths pairs:

                            0:30,34,1.0,0.0,1 / 3000:22,42,1.0,0.0,3

                            This will give us +/- 2 degrees at the near offsets, and +/- 10 degrees
                            at the far offsets. Note also that we are increasing the taper length
                            from 1 to 3 degrees as the offset increases.




        Prime Line Weighting
                         8. Parameterize the Sail line weighting.


17-24         ProMAX 3D Seismic Processing and Analysis                                              Landmark
                                            Chapter 17: ProMAX Marine 3D Geometry


              In the marine case we may elect to weight traces by a single sail line.
              In this case all of the traces that contribute to the CDP line are
              examined by their S_line trace header word. The sail line with the
              highest number of contributors is the prime sail line and traces that
              come from this sail line have the highest weight. You may elect to
              put an offset variant weight function based on the dominant sail line
              represented in the traces. In this example we will use an offset
              variant weighting function that weights the sail line highly for the
              near offsets and relaxes the weighting function toward the far
              offsets:

              0: 1.0, 0.1/ 3000: 1.0, 0.9

           9. Set the number of user-defined rules to NONE.

              You will have to cycle from ONE through FIVE back to NONE.

           10. Use the default of No so as not to request a verbose printout.

           11. Execute the flow.




Landmark                     ProMAX 3D Seismic Processing and Analysis          17-25
Chapter 17: ProMAX Marine 3D Geometry




QC Plots

                         The Assign CDP Flex Binning process writes a number of values to the
                         CDP Order Parameter (database) Files. You may elect to generate QC
                         plots using either DBTools (the default) or XDB Database Display. Try
                         some from each and decide which works best for you. In DBTools,
                         simply double-click the attribute to generate the display. XDB Database
                         Display allows you to view more than one attribute on the same display
                         (Database ¦ XDB Database Display, and then Database ¦ Get).

                         The values that are available for QC are:

                         •   CDP: GEOMETRY: FLEXFOLD

                         The number of traces contributing to each CDP after flex binning. One
                         of the goals of flex binning is to provide uniform fold. The uniformity
                         of this value indicates how well the flex binning worked.

                         •   CDP: FLXBINQC: MINOFF
                         •   CDP: FLXBINQC: MAXOFF

                         If the short or long offsets are missing from a flex binned CDP, these
                         values can be too high or too low, respectively.

                         •   CDP: FLXBINQC: MEANOFF
                         •   CDP: FLXBINQC: RMEANOFF

                         These values can show if long or short offsets are missing. At CDPs
                         where the values are high, short offsets are missing. If the values are
                         low, long offsets are missing. The expected mean offset is half the sum
                         of the first offset bin center and the last offset bin center. Ideally,
                         RMEANOFF, the ratio of the mean to the expected mean, should be 1.
                         In our case we specified 50 as our near offset and 3225 as our far offset.
                         This yields a predicted mean of 1725 meters.

                         •   CDP: FLXBINQC: STDDOFF
                         •   CDP: FLXBINQC: RSTDDOFF

                         These plots illustrates missing offsets if they happen to occur without
                         changing the mean offset. The ratio of standard deviation to expected
                         standard deviation will be 1 for an even offset distribution. If the ratio is
                         less than 1, short and/or long offsets are missing. If it is greater than 1,
                         middle offsets are missing.



17-26         ProMAX 3D Seismic Processing and Analysis                                     Landmark
                                                    Chapter 17: ProMAX Marine 3D Geometry


                    •   CDP: FLXBINQC: MEANAZTH

                    Indicates how well the Apply azimuth weighting rule in Flex Binning
                    worked.


      Produce QC plots from the database
                    1. Open the Database and use DBTools to generate the following pairs
                       of displays.

                    Fold:

                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord, FOLD, CDP (or
                        use the predined plot)
                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord, FLEXFOLD,
                        CDP


                    Offsets

                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord, MINOFF, CDP
                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord, MAXOFF, CDP


                    Mean Offsets

                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord, MEANOFF,
                        CDP
                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord, RMEANOFF,
                        CDP


                    Standard Deviation of Offsets

                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord, STDDOFF, CDP
                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord, RSTDDOFF,
                        CDP


                    Azimuth

                    •   View ¦ 2D Matrix CDP order: Xcoord, Ycoord,
                        MEANAZTH,CDP




Landmark                             ProMAX 3D Seismic Processing and Analysis     17-27
Chapter 17: ProMAX Marine 3D Geometry


                         Notice that by using the recommended parameters we have done a
                         reasonable job of stabilizing the fold and offset distributions for all the
                         CDPs.


        CDP Contribution and Null QC
                         There is one more set of QC plots that might be useful. We already know
                         that we have good offset distribution and fold but we don’t know how
                         many traces we have used more than once and how many we have
                         thrown away.

                         2. Using XDB Database Display, generate 2D (simple) plots of the
                            FLEXCDP#1, #2 and #3 attributes from the Trace database.

                         Any trace that is NULL for FLEXCDP#1 did not contribute to any CDP.
                         Non NULL CDP’s in #2 and #3 contributed to more than 1 CDP.




17-28         ProMAX 3D Seismic Processing and Analysis                                   Landmark
                                              Chapter 17: ProMAX Marine 3D Geometry




Expand Flex Binning

            Expand Flex Binning performs the second step of replicating or deleting
            traces per the bin assignments. This tool should be run before imaging
            processes like stack, DMO, prestack migration, AVO analysis, or
            velocity analysis.

            This tool accepts traces in any sort order and makes a copy of each input
            trace for each CDP bin to which it contributes. The tool finds the list of
            CDPs the trace contributes to by querying the TRC database parameter
            FLEXCDPS. If the trace contributes to no bins, it will be deleted. The
            tool simply reproduces one trace at a time, therefore, if the input data are
            CDP sorted, they would no longer be sorted on output from this tool.

            If a trace contributes to a CDP and its midpoint does not lie within the
            boundaries of the CDP bin, the trace’s source and receiver coordinates
            will be adjusted so that the trace’s adjusted midpoint lies at the same
            relative position in the new CDP as it did in it’s original bin. The tool
            does this so that 3D DMO will apply the trace to its new bin rather than
            just increasing its effect in the old bin.




                                                         shot and receiver
                                                         locations after
                                                         flex binning
                                                    X
                                     o
                    O
                                                    X     original shot and
                                                          receiver locations
                                     o
                    O



            We do not have the trace data for this example so we cannot run Expand
            Flex Binning.




Landmark                      ProMAX 3D Seismic Processing and Analysis           17-29
Chapter 17: ProMAX Marine 3D Geometry




17-30         ProMAX 3D Seismic Processing and Analysis   Landmark
                                                                             Chapter 18
              ProMAX Land Swath Geometry
Geometry Assignment is designed to create the standard Ordered Parameter File directories,
OPFs, and load standard ProMAX geometry information into the trace headers. The sequence of
steps depends upon available information. This chapter serves as an example of how to input the
geometry for a swath geometry. The main items of interest here are the ways to handle the spreads
rolling on and off the ends of the swaths and how to handle the cable roll between the swaths. The
Geometry Overview section in the Reference Manual and online helpfile provide further details of
the geometry assignment process.




Topics covered in this chapter:

                          t 3D Land Swath Geometry




Landmark                                     ProMAX 3D Seismic Processing and Analysis        18-1
Chapter 18: ProMAX Land Swath Geometry




3D Land Swath Geometry

                         In this exercise you will look at another Land 3D example, a more
                         common swath shoot.



                                                                      153-154
                                Receivers 1001-1154

                                Receivers 2001-2154




                              shots 10001 -
                              10153




                                                            shots 50001-
                                                            50153




                                  1              Receivers 8001-8154



                         Note the numbering sequence as described on the basemap. In this case
                         we have single station numbers that can be divided into line and station
                         numbers. We will choose this option in order to make the pattern
                         management easier. For the cable stations we will divide the 1001 - 1154



18-2          ProMAX 3D Seismic Processing and Analysis                                Landmark
                                           Chapter 18: ProMAX Land Swath Geometry


           stations into line 1 stations 1 - 154. The remaining receiver lines will be
           handled similarly. We will also divide the shot stations 10001-10153
           into line 10 stations 1 - 153. The remaining shot lines will be handled
           similarly as well.

           This exercise will present a couple of logistical problems in how to
           handle survey files and also how to roll the spread on and off at the end
           of the swaths using a single pattern definition per swath.




                       440’
           110’




                                                                 110’




                                Project Geometry Constants




Landmark                      ProMAX 3D Seismic Processing and Analysis          18-3
Chapter 18: ProMAX Land Swath Geometry


       Prepare the Line and run the Spreadsheet
                         1. Make a new line, called “3D Land 5 swath zig-zag.”

                         2. Build the following flow:


                        Editing Flow: 01 - spreadsheet

                        Add            Delete          Execute          View          Exit

                        3D Land Geometry Spreadsheet

                         3. Execute the flow.

                         4. Click Setup and enter the project constants:

                              •   Nominal Receiver Station Interval = 110 ft.

                              •   Nominal Source Station Interval = 110 ft. (or 155)

                              •   Nominal Crossline Separation = 440 ft.

                              •   Source stations numbers are not based on receiver station
                                  numbers

                              •   This project was recorded using a surface source.

                              •   The coordinate system is English units (feet).

                         5. Click OK.


       Receivers Spreadsheet
                         1. Open the Receivers Spreadsheet.

                         2. Use the File ¦ Import pulldown to open the ASCII file import
                            window.




18-4          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                               Chapter 18: ProMAX Land Swath Geometry


           3. Use the File ¦ Open pulldown menu to select the “5swath_recs”
              file from the directory that your instructor describes for you.




           4. Using the Format pull down enter an new columnar format
              description such as “5 swath receivers.”

           5. In the Column Import Definition window click Station in the
              parameter column and then paint the 3 columns that we will use as
              the station numbers.




            Note:

            We are splitting the station number into two numbers, one for the line and the
            remaining for the station along the line.




Landmark                       ProMAX 3D Seismic Processing and Analysis                     18-5
Chapter 18: ProMAX Land Swath Geometry


                         6. Select the remaining column definitions for Line, and the X and Y
                            coordinates.

                         Filter the file and remove unwanted comment cards

                         7. Click Filter and then respond to the window asking you to delete
                            any card that does not match the columnar format that was defined.




                         8. When the filtering is complete you should get a “Filtering
                            Complete” window and there should be a card at the top of the file
                            that says “Ignore Record for Import.”




18-6          ProMAX 3D Seismic Processing and Analysis                             Landmark
                                                 Chapter 18: ProMAX Land Swath Geometry


                   9. Click OK to dismiss the window.

                   10. Select Apply the format and Overwrite the values with the new
                       import values.




                   11. Click OK and the receivers spreadsheet should become populated
                       with the selected values.


      Sources Spreadsheet
                   1. Open the Sources Spreadsheet by clicking Sources in the main
                      spreadsheet menu window.

                   2. Select the File ¦ Import and File ¦ Open pulldown menus and
                      select the 5swath_shots file from the same directory where you
                      found the receivers file.

                   3. Using the Format pull down enter a new columnar format
                      description such as “5 swath shots.”

                   4. In the Column Import Definition window click Source in the
                      parameter column and then select all the columns used to store the
                      source numbers.




Landmark                            ProMAX 3D Seismic Processing and Analysis        18-7
Chapter 18: ProMAX Land Swath Geometry




                          Note:

                          We are splitting the station number into two numbers, one for the line and the
                          remaining for the station along the line.



                         5. Click Line in the parameter column and then select the first two
                            columns to be used as the line number(include a blank before the
                            first column)..




                         6. Complete the column definitions for the Station and X and Y
                            coordinates.

                         7. Click Filter to ignore any unwanted cards.

                         8. Select Apply the format and Overwrite the values in the
                            database. The Sources spreadsheet should now be populated with
                            the selected information.




18-8          ProMAX 3D Seismic Processing and Analysis                                            Landmark
                                         Chapter 18: ProMAX Land Swath Geometry


           9. Generate a Basemap from either the Sources or Receivers
              spreadsheet using the View ¦ View All ¦ Basemap pulldown
              menu.




           10. Use the Cross Domain Contribution (Double Fold) icon MB3
               function to measure the Azimuth of the cable lines. You should
               measure approximately 25 degrees.




Landmark                    ProMAX 3D Seismic Processing and Analysis           18-9
Chapter 18: ProMAX Land Swath Geometry


                         Click Setup from the main menu and input 25 degrees for the shot and
                         receiver azimuth.

                          Note:

                          In this mode the assignment mode is set to use the method of matching pattern
                          number in the SIN and PAT spreadsheets.

                          This is correct since we did not import patterns and did not run an extraction. In this
                          case we will have to specify patterns in the Patterns Spreadsheet.



        Patterns Spreadsheet
                         As an example we will define a pattern that is typical for a swath
                         shooting geometry. We will define a basic bi-symmetric split geometry
                         where we will have for any given shot 4 live cables and 60 traces on each
                         cable. The shots will be between the center two cables and between
                         traces 30 and 31 on each cable. There will be no gap in the split spread.

                         1. Open the Patterns Spreadsheet by clicking Patterns in the main
                            spreadsheet menu window.

                             Two windows will appear.




                         2. In the smaller window specify that there are a maximum of 240
                            traces per shot and that the number of traces per shot varies.

                         3. Click OK in the smaller window to dismiss it.

                         4. We can now specify the first pattern. Since we are using a line/
                            station relationship we will need a separate pattern for each swath.




18-10         ProMAX 3D Seismic Processing and Analysis                                                Landmark
                                         Chapter 18: ProMAX Land Swath Geometry


              For the First pattern mark a block of 4 cards and then fill the
              columns as shown in the next diagram.




              •   Fill Pattern starting at 1 and increment of 1
              •   Fill Chan From starting at 1 and increment by 60
              •   Fill Chan To starting at 60 and increment by 60
              •   Fill Chan Inc starting at 1 and increment by 0
              •   Fill Rcvr Line starting at 1 and increment by 1
              •   Fill Rcvr From starting at 1 and increment by 0
              •   Fill Rcvr To starting at 60 and increment by 0
              •   Fill Rcvr Inc starting at 1 and increment by 0


           5. Copy this pattern 4 times (one time for each remaining swath) and
              then change the cable numbers to match the pattern numbers on a
              per swath basis. Use the Edit ¦ Copy pull down to copy the
              pattern to a new one.




           6. Exit from the Patterns Spreadsheet selecting File ¦ Exit from the
              pulldown.




Landmark                    ProMAX 3D Seismic Processing and Analysis          18-11
Chapter 18: ProMAX Land Swath Geometry


        Complete the Sources Spreadsheet
                         Now that the patterns have been defined we can assign each shot to use
                         the appropriate pattern and then “SHIFT” the pattern for each shot.

                         1. Return to the Sources Spreadsheet.

                         2. You may elect to reorder the columns of the spreadsheet so that the
                            pattern and pattern shift cards appears near the Line and Station
                            columns for convenience. Use the Setup ¦ Order pull down and
                            then click on the column headers in the order you want the to
                            appear. Use MB2 on the last column heading of interest.

                         3. For all of the shots in the first swath (on line 10) we will use pattern
                            number 1 and then we will shift the pattern by -29 for the first shot
                            and increment the pattern shift by 1 for each shot.

                         4. Complete the pattern number and pattern shift entries for all shots
                            in all 5 swaths using multiple Find and Fill operations.

                         5. When complete exit from the Sources spreadsheet using the
                            File ¦ Exit pulldown.


        Trace Assignment
                         This exercise illustrates CDP binning procedures. For this example we
                         will automatically compute a CDP grid based on some initial known
                         values and then apply the grid using the batch CDP Binning* process.




18-12         ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                          Chapter 18: ProMAX Land Swath Geometry


           1. In the main menu, click Bin.

              A submenu appears with options for Assigning the traces to
              midpoints, defining the bin grid, binning the data, quality controlling
              the binning, and finalizing the database.




           2. Select to Assign midpoints by Matching pattern number in the
              SIN and PAT spreadsheets, and click Ok.

              In this case the Assignment step is performing the following
              calculations:

              •   Computes the SIN and SRF for each trace and populates the
                  TRC OPF

              •   Computes the Shot to Receiver Offset (Distance)

              •   Computes the Midpoint coordinate between the shot and
                  receiver.

              •   Computes the Shot to Receiver Azimuth.




Landmark                    ProMAX 3D Seismic Processing and Analysis         18-13
Chapter 18: ProMAX Land Swath Geometry


                            An Assignment Warning window will pop up warning that some or
                            all of the data in the Trace spreadsheet will be overwritten. Click
                            Proceed.




                            A number of progress windows will flash on the screen as this step
                            runs. A final Status window should notify you that you Successfully
                            completed geometry assignment. Click Ok.

                            If this step fails, you have an error in your spreadsheets somewhere.
                            Not much help is given to you, but the problems are usually related
                            to the spread and/or pattern definitions.




18-14         ProMAX 3D Seismic Processing and Analysis                                Landmark
                                                   Chapter 18: ProMAX Land Swath Geometry


      Spread QC after Trace Assignment
                    1. Open the Receiver Spreadsheet and generate a basemap using
                       the.View ¦ View All ¦ Basemap pull down menu.




                    2. Use the Cross Domain Contribution (Double Fold) icon MB1 and
                       MB2 functions to view which receivers have been defined to be live
                       for each shot and also to see which shots contribute to each receiver.
                       You should observe a symmetric split spread of four cables that
                       rolls on and off the spread at the ends of the swath.

                    3. Exit from the XYgraph and the Spreadsheet using the
                       File ¦ Exit ¦ Confirm and File ¦ Abort pull down menus
                       respectively.




Landmark                              ProMAX 3D Seismic Processing and Analysis        18-15
Chapter 18: ProMAX Land Swath Geometry


        Automatic Bin Calculation and QC
                         1. Select Bin midpoints and click Ok. You should get the following
                            window:




                         2. Set the Azimuth=25, Grid Size in X = 55, Grid size in Y=55, Bin
                            Space Name, Minimum offset to Bin=0.0. Offset Bin Increment
                            =110 and select to select Inlines to be parallel to grid Y axis,
                            which is parallel to the defined azimuth. In our case, this is parallel
                            to the cable.




18-16         ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                        Chapter 18: ProMAX Land Swath Geometry


           3. Click Calc Dim.

              The Calc Dim operation computes the origin of the grid and the
              Maximum X and Y dimensions.




           4. Save the grid definition by clicking Save.

           5. Click Cancel to exit this window.




Landmark                    ProMAX 3D Seismic Processing and Analysis     18-17
Chapter 18: ProMAX Land Swath Geometry


        QC the Calculated Grid
                         1. Select Define binning grid from the main binning window and click
                            Ok.




                            This will bring up a small map window.

                         2. Select Display ¦ Midpoint ¦ Control Points ¦ Black
                            (depending on the color of the background).




                         You should get the following plot:




18-18         ProMAX 3D Seismic Processing and Analysis                            Landmark
                                           Chapter 18: ProMAX Land Swath Geometry




                          Mid-point Scattergram for CDP Binning

           3.    Click Grid ¦ Open and select the grid name that you saved from
                the Calc Dim operation.

                This step overlays the bin grid on your subsurface data.




Landmark                      ProMAX 3D Seismic Processing and Analysis    18-19
Chapter 19: Land Geometry Using SPS Survey Data


       Build Geometry from SPS files for Land 3D
                         1. Make a new line called “3D Land SPS input example.”

                         2. Build the following flow:


                        Editing Flow: 01 - spreadsheet

                        Add            Delete         Execute          View        Exit

                        3D Land Geometry Spreadsheet

                         3. Execute the flow.

                         4. From the global File command, select File ¦ UKOOA import.

                              Enter the directory name as described by your instructor and click
                              OK.

                         5. Choose the sps.r file from the list.




                         6. From the Format pulldown menu, open a list of saved formats and
                            choose STANDARD SHELL SPS Land 3D.




19-4          ProMAX 3D Seismic Processing and Analysis                                 Landmark
                                   Chapter 19: Land Geometry Using SPS Survey Data


           Separate the windows.




           7. Check the column definitions by clicking on the words in the
              Parameter column.

              Notice that there are two column definitions:

              •   one for the “S” and “R” cards, and

              •   one for the” X” cards.

              Also note that, if desired, the coordinates can be altered using the
              Math OP and Op Value columns.

           8. Click Apply and then select Overwrite all the data. Click OK.




           While the import is running, you will see a variety of Status windows.
           Eventually you will see a “Successfully Completed” window.



Landmark                    ProMAX 3D Seismic Processing and Analysis          19-5
Chapter 19: Land Geometry Using SPS Survey Data


                         There are still two more files to read. We have read the “R” file but still
                         need to read the “S” and “X” files.

                         9. Use the File ¦ Open pulldown menu from the UKOOA File
                            Import window and select sps.s file.

                         10. Click Apply and select Overwrite all the data. Click OK.

                         11. Use the File ¦ Open pull down menu from the UKOOA File
                             Import window to access the “sps.x” file.

                         12. Click Apply and select Overwrite all the data. Click OK.

                         13. Quit from each of the column definition windows and select
                             File ¦ Exit from the main import window.


       Setting Project Constants
                         1. From the main menu, click Setup and input the following
                            information:

                         •      50 m receiver station interval

                         •      60 m source station interval

                         •      360 m crossline separation

                         •      The source stations are not based on the receiver station numbers.

                         •      This data were recorded using a surface source and the
                                measurement system is metric.

                                We will measure the azimuths on a basemap generated from the
                                receivers spread sheet.

                             Note:

                             Note that the Assignment mode is set to the third option of Matching line and station
                             numbers in the SIN and PAT spreadsheet

                             This mode is generally reserved for SPS input where every shot gets a separate
                             pattern defined for it.



                         2. Click Ok.




19-6          ProMAX 3D Seismic Processing and Analysis                                                 Landmark
                                              Chapter 19: Land Geometry Using SPS Survey Data


                    3. Generate a basemap of the project by opening the Receivers
                       Spreadsheet and selecting View ¦ View All ¦ Basemap.


      Determine Primary Azimuth for Binning
                    4. Use the “Double Fold” icon to measure the azimuth of the receiver
                       lines.




                         You should measure a value of approximately 97.5 degrees East of
                         North.

                     Note:

                     The cross domain plot only works after the first binning step is completed.



                    5. Click Setup and enter the 97.5o azimuth for both the shots and
                       receivers.

                    6. Exit from the Setup window by clicking OK.

                    7. Exit from the Receivers Spreadsheet by selecting File ¦ Exit.

                    8. Exit from the XYgraph using File ¦ Exit ¦ Confirm.


      Trace Assignment
                    This exercise illustrates CDP binning procedures. For this example we
                    will automatically compute a CDP grid based on some initial known
                    values and then apply the grid using the batch CDP Binning* process.




Landmark                                ProMAX 3D Seismic Processing and Analysis                 19-7
Chapter 19: Land Geometry Using SPS Survey Data


                         1. In the main menu, click Bin.

                             A submenu appears with options for Assigning the traces to
                             midpoints, defining the bin grid, binning the data, quality controlling
                             the binning, and finalizing the database.




                         2. Select to Assign midpoints by using Matching line and station
                            numbers in the SIN and PAT spreadsheets, and click Ok.

                             In this case the Assignment step is performing the following
                             calculations:

                             •   Computes the SIN and SRF for each trace and populates the
                                 TRC OPF

                             •   Computes the Shot to Receiver Offset (Distance).

                             •   Computes the Midpoint coordinate between the shot and
                                 receiver.

                             •   Computes the Shot to Receiver Azimuth.




19-8          ProMAX 3D Seismic Processing and Analysis                                  Landmark
                                           Chapter 19: Land Geometry Using SPS Survey Data


                       An Assignment Warning window will pop up warning that some or
                       all of the data in the Trace spreadsheet will be overwritten. Click
                       Proceed.




                       A number of progress windows will flash on the screen as this step
                       runs. A final Status window should notify you that you Successfully
                       completed geometry assignment. Click Ok.

                       If this step fails, you have an error in your spreadsheets somewhere.
                       Not much help is given to you, but the problems are usually related
                       to the spread and/or pattern definitions.


      Spread QC after Trace Assignment
                    1. Open the Receiver Spreadsheet and generate a basemap using
                       theView ¦ View All ¦ Basemap pulldown menu.




                    2. Use the Cross Domain Contribution (Double Fold) icon MB1 and
                       MB2 functions to view which receivers have been defined to be live
                       for each shot and also to see which shots contribute to each receiver.
                       You should observe a symmetric split spread of four cables that
                       rolls on and off the spread at the ends of the swath.




Landmark                              ProMAX 3D Seismic Processing and Analysis          19-9
Chapter 19: Land Geometry Using SPS Survey Data


                         3. Exit from the XYgraph and the Spreadsheet using the
                            File ¦ Exit ¦ Confirm and File ¦ Abort pulldown menus
                            respectively.


        Automatic Bin Calculation and QC
                         1. Select Bin midpoints and click Ok. You should get the following
                            window:




                         2. Set the Azimuth=97.5, Grid Size in X = 30, Grid size in Y=25, Bin
                            Space Name, Offset Bin Increment=50 and select Inlines to be




19-10         ProMAX 3D Seismic Processing and Analysis                             Landmark
                                 Chapter 19: Land Geometry Using SPS Survey Data


              parallel to grid Y axis, which is parallel to the defined azimuth. In
              our case, this is parallel to the cable.




           3. Click Calc Dim.

              The Calc Dim operation computes the origin of the grid and the
              Maximum X and Y dimensions.




           4. Save the grid definition by clicking Save.



Landmark                    ProMAX 3D Seismic Processing and Analysis       19-11
Chapter 19: Land Geometry Using SPS Survey Data


                         5. Click Cancel to exit this window.


        QC the Calculated Grid
                         1. Select Define binning grid from the main binning window and click
                            Ok.




                             This will bring up a small map window.

                         2. Select Display ¦ Midpoint ¦ Control Points ¦ Black
                            (depending on the color of the background).




                         You should get the following plot:




19-12         ProMAX 3D Seismic Processing and Analysis                            Landmark
                                            Chapter 19: Land Geometry Using SPS Survey Data


                                   Mid-point Scattergram for CDP Binning

                    3. Select Grid ¦ Open and the grid name that you saved from the
                       Calc Dim operation.

                         This step overlays the bin grid on your subsurface data.

                         Because of the density of the display a zoom will help show and QC
                         the results.

                         You may elect to alter the grid by using any of the interactive grid
                         editing icons if desired. (There should be no need to alter the grid.)

                    4. Exit the XYGraph by selecting File ¦ Exit ¦ Confirm.

                    5. Close the 3D Binning and QC window by clicking Cancel.

                    6. Select File ¦ Exit from the main spreadsheet menu to exit the
                       Geometry Spreadsheet.


      Complete CDP Binning using Batch CDP Binning
                    This exercise completes the CDP binning and database finalization
                    steps.

                    1. Build and execute the following flow:


                   Editing Flow: 02 - CDP Binning

                   Add            Delete          Execute           View         Exit

                   CDP Binning*
                         Binned Space Name ------- “your grid”

                         This process will perform the CDP binning and Finalization steps in
                         a batch job instead of interactively using the spreadsheet.

                    2. Once the Binning is complete you can generate the QC plots using
                       the database display tools.




Landmark                               ProMAX 3D Seismic Processing and Analysis         19-13
Chapter 19: Land Geometry Using SPS Survey Data




19-14         ProMAX 3D Seismic Processing and Analysis   Landmark

				
DOCUMENT INFO
Shared By:
Categories:
Tags: promax, seismic
Stats:
views:3447
posted:11/17/2011
language:English
pages:474
Description: ProMAX 3D : Seismic Data Processing 3D