3D Processing
DP START Oslo
2004
At the end of this Session, you will be able to:
• Define the term 'binning' as used in processing.
• Define the term 'bin' as used in processing.
• Define the term 'inline (row)' as used in
processing.
• Define the term 'crossline (column)' as used in
processing.
• Define the term 'nominal fold' as used in binning.
• Define the term 'maximum fold' as used in
binning.
• Define the term 'coverage plot (areal map)' as
used during binning.
• Define the term 'azimuth binning' as used in
processing.
• Oslo
DP START Define the term ‘flex binning' as used in
2004
processing.
At the end of this Session, you will be able to:
• Define the term 'redundancy editing' as used in
binning.
• Define the term 'lateral smear' as used during
binning and stacking.
• Define the term 'azimuth' as used in processing.
• Be able to calculate CMP intervals
• Be able to describe & calculate nominal near & far
offsets
• Understand what is meant by conventional binning
• Describe the Omega Master Grid
• Explain what is meant by ordinal values
DP START Oslo
2004
At the end of this Session, you will be able to:
• Describe how the presence of cable feathering
during marine acquisition can, if unaccounted for,
be detrimental to processed seismic data quality.
• Under stand which 3D prestack traces contribute
to a 3D stacked trace.
• Describe how 3D stacks are QC’d
• Comprehend that the terms reciver, group,
location, station mean the same think &
understand the meaning.
• Be able to calculate how many sub surface tracks
in 1 sailline & nominally how many in a survey.
DP START Oslo
2004
Session Flow:
• Why 3D.
• Definations; Revision of previous presentation
• The Geometry of a 3D land survey (not tested)
• Review of Marine Geometry - 2D & 3D
• Feathering & Need for Positioning
• 3D Gridding / binning
• Quality Control of 3D Binning
DP START Oslo
2004
Why 3D ?
Boat
Deep Canyon
Coarse 2D Grid Three reflections from same structure
DP START Oslo
2004
2D Surveys
2D Reconnaissance Survey 2D Detailed Survey
DP START Oslo
2004
A 3D Survey Grid
Volume of data
DP START Oslo
2004
Session Flow:
• Why 3D.
• Definations; Revision of previous presentation
• The Geometry of a 3D land survey (not tested)
• Review of Marine Geometry - 2D & 3D
• Feathering & Need for Positioning
• 3D Gridding / binning
• Quality Control of 3D Binning
DP START Oslo
2004
Definitions
NEAR TRACE GROUP FAR TRACE
GROUP 1 / TRACE 1 INTERVAL GROUP n
Source
NEAR TRACE
OFFSET Total „active‟ streamer length
(NTO or Leadin) (centre near group------------------------------------------centre far group)
FAR TRACE OFFSET (FTO)
((Number of groups -1) x Group interval) + Near Trace Offset
• [TRACE/GROUP] OFFSET refers to distances relative to center of source
• OFFSETS of TRACES/GROUPS measured to the center of streamer sections
• OFFSETS important measurement derived from field geometry from a DP perspective
• Nearest group is normally GROUP 1
DP START Oslo
2004
Calculations
GROUP
INTERVAL
NEAR TRACE FAR TRACE
25m
GROUP 1 GROUP 240
Source
NEAR TRACE
OFFSET Total „active‟ streamer length
100m (centre near group------------------------------------------centre far group)
FAR TRACE OFFSET (FTO)
((Number of groups -1) x Group interval) + Near Trace Offset
• Given the above diagram calculate the following
•Total Active Streamer length
•Far Trace Offset
DP START Oslo
2004
More Calculations
For Marine acquisition parameters :
Near trace offset 310m
Group interval 50m
Number of groups 120
Calculate the following :
1) Total active length of streamer ________
2) Offset to far receiver group ________
3) Offset to receiver group number 78 ________
4) Offset of CMP for receiver group number 60 ________
( ie. How far from the source is the cmp generated by group number) 60?
DP START Oslo
2004
2D Marine layout
Source
Receiver
Common Mid Point
S R
DP START Oslo
2004
2D Land Field Layouts
Symmetric split spread
Asymmetric split spread
End on
DP START Oslo
2004
Calculations
NB. True where G.I and Shot interval are
integer multiples of each other and „end-on‟
CMP INT = (Groupint/2)
shooting.
For other configurations, you may have to
Number of NEW cmps / Shot = (Shot int / CMP int) draw to confirm fold.
Fold = (Groupint/Shot int) * (No.channels/2)
IN OMEGA THE FIRST LIVE CMP IS
First live CMP = [( FTO/2 ) / CMP int] + 1 USER DEFINED - IT DEFAULTS TO 1!
THIS FORMULA IS APPLICABLE TO
SOME OLDER SOFTWARE SYSTEMS
First full fold CMP = first live CMP + [(fold - 1) * (no. new cmps per shot) ]
Last CMP with maximum fold = first live CMP + [((no.shots - 1) * (no. new cmps per shot)) + (no. new cmps per shot - 1)]
Last CMP = last full fold CMP + [(fold - 1) * (no. new cmps per shot) ]
DP START Oslo
2004
Calculations
NB. True where G.I and Shot Interval are
CMP INT = (Groupint/2) integer multiples of each other.
For other configurations, you may have to
draw to confirm fold.
Number of NEW cmps / Shot = (Shot int / CMP int) In this case, the configuration is „regular‟.
Fold = (Groupint/Shot int) * (No.channels/2) = (25/25) * (10/2) = 5
First live CMP = 1 because we used the Omega default
First full fold CMP = first live CMP + [(fold - 1) * (no. new cmps per shot) ]
= 1 + [ (5 - 1) * 2 ]
= 9
Last CMP with maximum fold = first live CMP + [((no.shots - 1) * (no. new cmps per shot)) + (no. new cmps per shot - 1)]
= 1 + [((20 - 1) * (2)) + (2 - 1)]
= 40
Last CMP = last full fold CMP + [(fold - 1) * (no. new cmps per shot) ]
= 40 + [(5 - 1) * 2]
= 48
DP START Oslo
2004
Definitions
Trace no 1 2 3 45 67 89
Trace Decimation- This process
involves reducing the data volume
by dropping or discarding traces.
Typically every second trace in a
shot record is discarded.
Trace Summation- This process
involves reducing the data volume
by summing adjacent traces.
Trace no 1 2 3 4 5
DP START Oslo
2004
What happens to our geometry
Trace Decimation
NEAR TRACE FAR TRACE
GROUP 1 / TRACE 1 GROUP n
new group interval
unchanged new cmp interval new FTO
new group no.
** fold of coverage unchanged!
NTO FTO
DP START Oslo
2004
What happens to our geometry
Trace Summation
NEAR TRACE FAR TRACE
GROUP 1 / TRACE 1 GROUP n
new group interval
new NTO new cmp interval new FTO
new group no.
** fold of coverage unchanged!
NTO
FTO
DP START Oslo
2004
Session Flow:
• Why 3D.
• Definations; Revision of previous presentation
• The Geometry of a 3D land survey (not tested)
• Review of Marine Geometry - 2D & 3D
• Feathering & Need for Positioning
• 3D Gridding / binning
• Quality Control of 3D Binning
DP START Oslo
2004
Basic Marine Geometry
* Source
Receiver
Common Mid Point
Source Receivers
*
FIRST LIVE
RECEIVER
C
FIRST LIVE
CMP
8 7 6 5 4 3 2 1
CMP number
DP START Oslo
2004
Marine 2D Acquisition
PORT
* SAIL LINE
STARBOARD
• Produces a series of discrete 2d lines across the survey area
• Lines are Processed separately, although parameters will be the same
• For consistency ‘tie-lines’ may be recorded producing a coarse grid
of information
DP START Oslo
2004
Marine 3D Acquisition
DP START Oslo
2004
A bird‟s eye-view
Marine 3D geometry Source
• Single boat Receiver
Common Mid Point
• Dual source
• Multi streamer
Port Starboard
Streamer separation (100m) Streamer separation (100m)
Source Separation (50m)
Source2 Source1
Streamer3 Streamer2 Streamer1
Line
Separation
(25m)
sub-surface lines
Session Flow:
• Why 3D.
• Definations; Revision of previous presentation
• The Geometry of a 3D land survey (not tested)
• Review of Marine Geometry - 2D & 3D
• Feathering & Need for Positioning
• 3D Gridding / binning
• Quality Control of 3D Binning
DP START Oslo
2004
Cable Feathering
No feathering
Feathering
DP START Oslo
2004
The Real Effect of Feathering
M
M(n)
If the marine cable is feathered by 10 degrees, the far end of the cable will be
displaced by 530m from the nominal straight shooting line.
This causes the midpoints to be displaced by 265m.
DP START Oslo
2004
Classifications of Geometry
Nominal layout
Projected co-ordinates
DP START Oslo
2004
Nominal Layout - Example
Source
Receiver
Inline
CMP
streamer 3
sub-surface tracks source2
PORT
streamer 2
SAIL LINE
sub-surface tracks STARBOARD
source1
streamer 1
• Multiple subsurface lines are recorded each pass of the boat
• Data forms a finely sampled volume of information.
• A Grid of bins is overlaid, each cmp position falling at the centre of a bin
DP START Oslo
2004
Projected Co-ordinates - Example
Source
Receiver
streamer 3
CMP
negative perpendicular
offsets
source2
PORT
streamer 2
SAIL LINE
STARBOARD
source1
positive perpendicular
offsets
streamer 1
group near
interval offset
In this exaggerated drawing of cable feathering, it is obvious that mid-point scatter needs to be sorted out
(via binning process) and properly Quality Controlled
DP START Oslo
2004
Real-Time Binning
Streamer
shape In-sea
Networks
The ability to monitor fold of coverage
during the acquisition stage.
Coverage
In some cases, the Navigators steer the plot
Vessel, and hence the CMPs. In other cases,
in-fill lines are shot if necessary to improve
the level of fold in each bin.
DP START Oslo
2004
Storage of Marine Positioning Information
Source and receiver positions are stored in UKOOA format
on tapes or diskettes. UKOOA stands for
(United Kingdom Offshore Operators Association).
Various formats:
P2/94, P2/91 and P2/86 = raw navigation data
P1/90 and P1/84 = processed navigation data
DP START Oslo
2004
P1/90 UKOOA Header - Data area
1
2
3
4
5
1) „V‟ is the vessel position.
2) „S‟ is active firing source.
3) „Z‟ is all source positions.
4) „T‟ is tailbuoy positions.
5) „R‟ is receiver positions.
DP START Oslo
2004
General
Receiver Info.
General
P1/90 UKOOA Header example
Streamer offsets.
Projection and spheroid.
Navigation processing Info
DP START Oslo
2004
Navigation / Seismic Data Merge
A separate Geometry
Database is created for each
Processed Sail Line
QC UKOOA
GEOMETRY
QC Database QC includes:
Fold Maps and
Shotpoint Maps.
Navigation / Seismic Data
GEOMETRY Seismic merge is carried out on a
Database Data Sail Line basis
After Merge QC
MERGE
includes:
LMO displays
Near Trace cubes
DP START Oslo
2004
Session Flow:
• Why 3D.
• Definations; Revision of previous presentation
• The Geometry of a 3D land survey (not tested)
• Review of Marine Geometry - 2D & 3D
• Feathering & Need for Positioning
• 3D Gridding / binning
• Quality Control of 3D Binning
DP START Oslo
2004
3-D Grids
Once X / Y coordinates are in the trace headers,
processing grids can be defined, or redefined, at
any stage as part of a processing job using
GRID_DEFINE sfm
DP START Oslo
2004
The Master Grid
The Master Grid is the basis of a 3D grid definition.
There are 3 parts to a Master grid Definition:
•The X/Y coordinates that define the location and extent of the grid
•The dimensions of the cells (bins) within the grid
•The specification of the ordinals
DP START Oslo
2004
Defining Corners of Master Grid
•The extent of the Master Grid is defined by specifying four points
•The centre of each corner cell is defined
MG4 MG3
Primary Direction
MG2 MG1
DP START Oslo
2004
Other Names for Grid Axes
•In common usage, the direction of the Primary Axis is called the
“in-line” direction. The axis is sometimes called the “shot” direction.
•Likewise, the Secondary Axis is referred to as the “cross-line”
direction. These terms vary among and within companies.
MG4 MG3
Cross-line
In-line
Primary Direction
MG2 MG1
DP START Oslo
2004
Defining Ordinals
Ordinals are defined by specifying the Primary and Secondary
ordinals to associate with the centre of the corner cell containing
MG1. Increments between ordinals at adjacent cell centres are
also defined.
MG4 MG3 3.0
2.0
MG2 MG1 1.0
40.0 30.0 20.0 10.0
DP START Oslo
2004
ORDINALS
•Primary ordinals always increase from MG1 to MG2
•Secondary ordinals always increase from MG1 to MG3
•Ordinal increments are therefore always “positive”.
•Ordinal values may be positive, negative or zero.
DP START Oslo
2004
Defining Cell (bin) Numbers
Cell number order is defined by specifying the starting corner
cell, and the grid axis.
PG4 PG3
12 11 10 9 3.0
8 7 6 5 2.0
4 3 2 1 1.0
PG2 PG1
40.0 30.0 20.0 10.0
DP START Oslo
2004
BINNING
Problem
Fold variations and irregular offset distributions within
CMP bins reduce the effectiveness of stacking
Solution
Analysing bin contents via a 3D database, and making
adjustments (where necessary via Flexi-binning) to achieve
a high degree of consistency in fold and offset distribution
The ideal binning strategy optimises stack quality without
introducing excessive lateral smear
DP START Oslo
2004
BINNING
Bin Interval (Inline)
The contents of a Bin
Bin Diameter (Xline)
Each Bin contains a collection of midpoints (CMP’s)
The midpoints within a bin will be stacked together.
There are two attributes for a stack trace:
a) Bin Centre
b) Bin Centroid - An average of co-ordinates
Centroid Ideally we have the nominal fold of coverage (in this case 6)
x and each midpoint is from a different offset group
x This is not likely to be the case for all bins in a survey.
Centre There may exist irregular offset distributions and low and/or
over fold areas
DP START Oslo
2004
BINNING OPTIONS
• CONVENTIONAL BINNING
• FLEXI-BINNING
DP START Oslo
2004
Conventional Binning
Data is binned as acquired
• Each CMP location falls into a bin of nominal bin size
• All traces are accepted
Results:
• Variation of fold
• Irregular offset distribution
• Crossline scatter of midpoints within bins
This often results in lateral variation in fold, and thus reduced effectiveness of
processes such as velocity analysis and stacking.
DP START Oslo
2004
Flexible Binning
Data is binned by intelligent search and selection
• Bins are allowed to expand only until the gaps in offset
distribution are filled
• The expansion is allowed only up to a specified maximum
• Traces are assigned to and used in both bins
Results
• Fold is increased
• Offset distribution is optimised
• Lateral smear reduced to a minimum
DP START Oslo
2004
FLEXI-BINNING
Regularly spaced rectangular bins 3D Flexi-binning
DP START Oslo
2004
Flexi-Binning
•Flexi-binning is primarily used in marine processing
to regularise fold of coverage on pre-stack data.
Cable feather is mainly responsible for uneven fold.
•Improved fold leads to:
•better multiple attenuation
•improved normalisation within stack
•more constant signal-to-noise ratio
•reduced problem of zero-stackwords pre-stack
• However, in areas of steep dip, flexi-binning can
produce smearing
DP START Oslo
2004
Example of good offset distribution
(enabling good multiple attenuation)
Primary
Stack
Multiple
(After NMO corrections)
DP START Oslo
2004
Example of bad offset distribution
(multiple attenuation not so good)
Primary
Stack
Multiple
Two traces in the
same offset segment
DP START Oslo
2004
Data Example
DP START Oslo
2004
How Flexi-binning Works - diagram
50m
= Original cell (bin)
= Expanded cell (bin) 25m
25m
50m
Data from the
EXPANDED cell
can be used to fill in gaps
from the ORIGINAL cell
DP START Oslo 25m
2004
Dual Purpose Operation
•Aim is to have each offset represented in each cell (bin)
•Flexi-binning performs two operations:
•Reject (or down-weight) duplicate traces
•Copy traces from adjacent cells (bins) to account
for missing traces
DP START Oslo
2004
Flexi-binning on an offset plane
FLEX
Input
Identify empty cells
DP START Oslo
2004
Flexi-binning on an offset plane
R1
FLEX
R
S1
S
Input Output
Identify empty cells 1. Missing bins use cell expansion to find
nearest trace then “copy & move”
(plus header translation)
2. Duplicate traces in bins removed
DP START Oslo
2004
Results of „borrowing‟ a trace
If a trace is copied for use in another cell
two things happen:
• it is still available for use in its own (prime) cell
• the data is copied, and the trace header values
adjusted such that the midpoint falls at the
centre of the new cell
DP START Oslo
2004
Binning Example
Conventional Binning
42
What is the Fold in A? ______ Expansion
Percentage
100
16
What is the Fold in B? ______ 80 Bin C
60 Inline 103
46
What is the Fold in C? ______ 40 Crossline 2761
20
The nominal fold expected is 36.
Has this level been met? Bin B
Inline 102
Flexible Binning Crossline 2761
How much should Bin B expand? 20
40 Bin A
40% (20% Overlap) 60 Inline 101
80 Crossline 2761
36
What is the Fold in B? ______ 100
(assume all unique offsets.)
DP START Oslo
2004
Golden Rule of Flexi-binning
A trace is only copied from the expanded cell if an
equivalent trace doesn‟t already exist in the primary
cell.
So, even if the expanded cell is large, it‟s full extent
is very rarely used.
We stress this to clients who are concerned about
introducing smearing to their data
DP START Oslo
2004
Dilemma for trace selection
•Case 1 - aim for one trace per offset bin
•If two traces are available for the same offset
range, which trace should I reject?
•Or if a trace is missing, which trace should
I copy?
•Case 2 - keep all traces
•No trace rejection
•Do I treat all traces the same?
DP START Oslo
2004
Trace Selection Options
• Each trace is assigned a „quality factor‟
Various criteria can be used, the simplest is
the distance of the midpoint from the cell centre
• Areas of the expanded cell are assigned
preferences
On option, traces can be weighted differently
depending on their position within the expanded cell
DP START Oslo
2004
Session Flow:
• Why 3D.
• Definations; Revision of previous presentation
• The Geometry of a 3D land survey (not tested)
• Review of Marine Geometry - 2D & 3D
• Feathering & Need for Positioning
• 3D Gridding / binning
• Quality Control of 3D Binning
DP START Oslo
2004
QC of Binning
BINNING
Fold of coverage plots
SEISMIC QC
Inline and Crossline gathers and stack displays
DP START Oslo
2004
Fold of Coverage Plot - Before Flex
DP START Oslo
2004
Fold of Coverage Plot - After Flex
DP START Oslo
2004
QC of Binning
Conventional Flexi-binning Flexi-binning
25m bins 37.5m bins 50m bins
DP START Oslo Cross line Stack QC
2004
Major Binning Considerations
• Accurate Surveying is very important
• Each Bin must have uniform distribution of offsets
– Only Short offsets - Useless for Multiple Attenuation
– Only Far offsets - Jeopardizes Velocity Analysis
• Greatest density of midpoints (ideally) at Bin Center
• Minimize Src-Rcvr Azimuths in significant dip areas
• Bins can vary in Xline direction, but usually not in inline
DP START Oslo
2004
3D STACK
Stack data is eventually stored on disk or
workstation for 3D interpretations
3D Stacking is the summation of midpoints within
a bin to form a stacked trace at the bin centre.
Stack is the most effective method for improving
the signal to noise ratio of seismic data.
DP START Oslo
2004
STACK QC
QC During Stack
Crossline stack displays check for
- progress of stack
- positioning and timing errors
- amplitude variations
- tidal variations
Fold plots
- provides daily monitoring of stack
progress
- shows number of traces that remain
to be stacked, by using information
from binning database.
DP START Oslo
2004
STACK QC
QC After Stack
Inline displays
- all inlines to be displayed
- match to pre-stack trials
- check for spikes or noise problems
Crossline displays
- selection of crosslines to be
displayed
- check for timing jitter
amplitude variations
structure discontinuities
Isotime displays - Time-slices
DP START Oslo
2004
BINNING
Suggested self-study:-
CBT:
1. Data Processing General
3D Processing Flow
a - Positioning and Binning
b -Velocity Fields
c - 3D Stack
On-line Technical Documentation in Omega
1. About Flexibinning and Suites of SFM’s
associated with this process
DP START Oslo
2004
Session Flow:
• Why 3D.
• Definations; Revision of previous presentation
• Review of Marine Geometry - 2D & 3D
• Feathering & Need for Positioning
• 3D Gridding / binning
• Quality Control of 3D Binning
• The Geometry of a 3D land survey
DP START Oslo
2004
A Land 3D Survey in Saudi Arabia
RECEIVER PARAMETERS
12 Active Receiver Lines – Spaced 200m Apart
192 Live Geophone Stations (Channels) per Line
50m Geophone Station Interval In-Line
50m x 50m Geophone Pattern
6 Geophone Strings per Station
12 Geophones per String
Each Receiver Line = 192 x 50m = 9.60Km Long
12 Lines Spaced at 200m = 2.4Km Wide
PROSPECT AREA “LIVE” Spread Covers an Area of 23.04 Sq Kms
SOURCE PARAMETERS
2 Fleets of Vibrators
5 Active Vibrators per Fleet plus 1 Spare
1 Sweep per VP
16 Second Sweep Time
6 Second Listen Time
Vibrators In Centre of Live Spread
DP START Oslo
2004
Client Parameters – Prospect Area & Blocks
PROSPECT AREA
RECEIVER PARAMETERS
Each Receiver Line = 192 x 50m = 9.60Km Long
The crew has 5760 Stations of Geophones
excluding Spare Strings to lay on 12+0.5 Lines
= 460 Stations per Receiver Line x 50m
= 23.04 Kms of Geophones per Receiver Line
LENGTH 60
Kms
But the Prospect is 30Kms Wide, so it is
necessary to split the Prospect into 2 Blocks
WIDTH 30 Kms
DP START Oslo
2004
Agenda
Introduction
Overall Process Flow
Crew Operations
• Acquisition Parameter Selection
• Surveying Operations
• Recording Operations
• Seismology Operations
• Logistics Support
Productivity
Finance
Some of the Differences Between Land/TZ and Marine Acquisition
Conclusions
DP START Oslo
2004
Surveying the Block
SURVEY PARAMETERS
Vibrator and Receiver Centre of Gravity Points are positioned.
All Points located to an accuracy of ±3metre against the Preplan then the
Actual location is measured to an accuracy of ±1 metre.
Typically there are 12 GPS Surveying Crews who average 300 Points per Day.
They walk over 15 Kms across country daily.
Offset Points must be positioned when obstacles e.g. pipeline, roads prevent
desired positioning.
DP START Oslo
2004
Statistics slide
A typical Survey Section section for a large 3-D Desert crew with 22
receiver lines and 50 m Receiver & Source intervals would have :
• 3 Personnel Carriers
• 3 Light vehicles
• 10 GPS backpacks
• 2 Base stations
• 15 GPS operators
• 12 Chainmen
• 6 Peg/Stake men
• 3 foremen
• 8 surveyors
• 2500 points surveyed / day ( Source & Receiver )
DP START Oslo
2004
Agenda
Introduction
Overall Process Flow
Crew Operations
• Acquisition Parameter Selection
• Surveying Operations
• Recording Operations
• Seismology Operations
• Logistics Support
Productivity
Finance
Some of the Differences Between Land/TZ and Marine Acquisition
Conclusions
DP START Oslo
2004
Receiver Spread in A Single Block
LIVE SPREAD TRANSVERSE LINE (BACKBONE)
1
2
3
WIDTH 9.6 Kms
4
5
6
RECORDING TRUCK
7
8
9
10
11
12
RECEIVER LINES (GROUND NETWORK)
BLOCK WIDTH 23.04 Kms
DP START Oslo
2004
Movement of Vibrators & Live Spread
LIVE SPREAD TRANSVERSE LINE (BACKBONE)
1
2
3
4
5
6
VIBRATORS RECORDING TRUCK
7
8
9
10
11
12
13
14
DP START Oslo
2004
Movement of Receivers
Back Crew (Picking Up Spread)
1
2
3
4
5
6
Vehicles
7 Moving
VIBRATORS Spread
8
9
10
11
12
13
Front Crew (Laying Spread)
14
DP START Oslo
2004
Front Crew on a land Seismic Crew
DP START Oslo
2004
Desert Crews-Saudi-Layout
DP START Oslo
2004
Desert Crews-Saudi-Pickup
DP START Oslo
2004
Individual Geophone Stations
4 5 .8 3 m
4 5 .8 3 m
4 .1 7 m 8 .3 3 m
GEOPHONE STATION CENTRE OF GRAVITY
INDIVIDUAL GEOPHONES
DP START Oslo
2004
Movement of Vibrators
25 m 50 m
R E C E IV E R L IN E 5
25 m
X X X X
V IB R A T O R S E T 1
V IB R A T O R S E T 2
X X X 200 m X
X X X X
R E C E IV E R L IN E 6
X VIBRATOR SET 1 CENTRE OF GRAVITY
VIBRATOR SET 2 CENTRE OF GRAVITY
RECEIVER STATION CENTRE OF GRAVITY
DP START Oslo
2004
Vibrator Pattern (VP)
50 m
X X
4 5 .0 4 m 1 1 .2 5 m
X X
X VIBRATOR POINT CENTRE OF GRAVITY
VIBRATOR SET 1 PAD POSITIONS
VIBRATOR SET 2 PAD POSITIONS
RECEIVER STATION CENTRE OF GRAVITY
DP START Oslo
2004
The Vibrators Moving (In Kuwait)
DP START Oslo
2004