Long Term Integrity of Deep Water Systems by HC120727213242

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									Long Term Integrity of Cement
          Systems

          June 19, 2003
                 Agenda
•   Participants/Financials
•   Project Focus/Management
•   Project Tasks
•   Summary Action Items
•   API Test Data
•   Seal Tite Test Results
               Participants
• Commitments
  – MMS, Petrobas, Unocal, BP, ExxonMobil
  – Saudi Aramco, ONGC, Conoco, AGIP
  – DOE, *PDVSA, HES, Dominion
• Potentials
  – Marathon, Stat Oil, Devon,
                Financials
• Commitments - $50k each
  – $650k 13 Companies
  – Potential additional $100 to 150k
  – To date - $450
• Project Timing – 18 months
      Management of Project
• Fred Sabins – Project Manager
• Bryan Simmons – Operations Manager
• Lab support
  – CSI
  – Westport Rock Mechanics
• Mathematical Analysis – University of
  Houston
• Rock Properties Instruments - Chandler
     Project Communications
• Steering Committee – Voting Members
  – Meeting notes/ voting privileges


• Quarterly Progress Report/Meeting
  – June 2003
  – October 2003
            Project Objective
• Determine the cement system properties that
  effect the ability of cements to seal fluids
   – Primarily in Deep Water
   – General application
• Develop a correlation of the cement properties to
  performance
• Determine laboratory methods to determine key
  properties
                      Tasks
•   Task 1 – Problem Analysis
•   Task 2 – Property Determination
•   Task 3 – Mathematical Analysis
•   Task 4 – Testing Baseline
•   Task 5 – Refine Procedures
•   Task 6 – Composition Matrix
•   Task 7 – Conduct Tests
•   Task 8 – Analyze Results
•   Task 9 – Decision Matrix
               Testing Program

• Deep Water/All Conditions
• Cement Slurries
  –   Class A
  –   Foamed Cement
  –   Bead Cement
  –   Class H
  –   Latex Cement
  –   Fibers, Expansion additives
          Performance Issues
• Flow of fluids
  – Around the cement
     • Bonding, microannulus, deformation
  – Through the cement matrix
     • Cracking, permeability changes
  – Under stress
     • Pressure, temperature
     • Cycling conditions
          Testing Program
• Cement design performance Mathematical
  modeling
• Mechanical properties
• Performance
  Cement Design Performance
• Standard cement design testing
  –   Thickening time
  –   Compressive strength
  –   Rheology
  –   Free water
      Mathematical Modeling
• University of Houston Numerical Model
• Stress states with thermal and pressure
  cycling
• Tensile stresses of 1,000 to 2,000 psi
  possible
• Formation strength governs failure
         Mechanical Properties
•   Tensile strength
•   Young’s modulus
•   Poisson's ratio
•   Hydrostatic pressure cycling
•   Fatigue/anelastic strain
          Tensile Strength
• Brazilian Test Method
• Tensile Strength Young’s Modulus
• Maximum Yield
             Testing Device
                          Force applied in
                           this direction
• Samples are oriented
  on side for tensile
  strength tests.
• Force is applied by
  constant displacement
  of bottom plate.
Tensile Strength and Young’s Modulus
       Slurry         Tensile Strength(psi)   Young’s Modulus
   Foam(12ppg)                253                 3.23 E 4

       Type I               394/213            19.15/8.16 E 4


 Type I with Fibers          1071                 9.6 E 4

       Latex                  539                 5.32 E 4

  Latex with Fibers           902                 8.5 E 4
        C Young’s Modulus
• Compressional Tests
• Confining Loads – Defined by 0psi break
  – Base line 14 day cure
• Acoustic Data
• Poisson’s Ratio
        Young’s Modulus Results
    Slurry     Confining Pressure   Young’s Modulus
 Composition                             (psi)
Type I                0                 16.7 E 5
                     1500               11.1 E 5
                     5000               9.1 E 5
12-ppg Foam           0                 5.8 E 5
                     500                6.8 E 5
                     1000               6.1 E 5
12-ppg Bead           0                 9.5 E 5
                     500                8.1 E 5
                     1000                1E6
Latex                 0                 5.6 E 5
                     250                8.9 E 5
                     500                9.4 E 5
               Correction

• Recently discovered correction factor
  accounts for instrument strain
• Next report will have corrected
  information
      Poisson’s Ratio Results
• Variable depending on:
  – Stress Rate
  – Slurry Type
  – Air Entrainment
          Poisson Ratio, 50 psi
              250 psi/min
Slurry    Failure   V Radial
          psi
Foam      3100      0.000*
Bead      4100      -0.01*
Class H   6450      0.0012
SMS       920       0.005
Type 1    6500      0.1
          Strain Amounts/Cycling
Slurry     1000 psi   2000 psi   3000 psi   4700 psi

Foam       0.00261    0.00167    -------

Bead       0.00191    0.00158    0.00115

Class H    0.00161    0.00150    0.00102

Type 1     0.00108    0.00080    0.00069
     Acoustic Measurements
• Chandler’s New Mechanical Properties
  Device
    Anelastic Strain Procedure
• Measure failure stress.
• Apply stress equal to 25%, 50%, or 75% of
  failure.
• Measure deformation.
                                Anelastic Strain Results
                                                Bead Slurry, Confining Pressure = 0 psi,
                                                250 psi/min, cycle 25% of failure stress

                    2000
                                          Cycle 1
                    1800
                                          Cycle 2
                    1600                  Cycle 3
Axial Stress(psi)




                    1400                  end

                    1200

                    1000

                    800

                    600

                    400

                    200

                      0
                           0   0.0005   0.001    0.0015    0.002    0.0025    0.003    0.0035   0.004   0.0045   0.005
            Performance Tests
• Shear Bond Measurements (Cycling conditions)
   – Soft Formations
   – Intermediate Formations
   – Hard Formations
• Annular Seal/Hassler Sleeve (Cycling Conditions)
   – Soft Formations
   – Intermediate Formations
   – Hard Formations
                   Shear Bond Molds
• Each sample is cured in a simulated hard, intermediate, and
  soft formation configuration.
• A steel external pipe is used to simulate a hard formation;
  PVC to simulate an intermediate formation.


                                                              External Pipe

                        External Pipe
                                                              Cement

                        Cement
                                                              Plastisol


                        Internal Pipe                         Internal Pipe




       Simulated Hard or
    Intermediate Formation              Simulated Soft Formation
     Old Temperature Cycling
           Procedure
• After curing, entire sample heated and
  cooled in water baths from 45 to 180 and
  back.
• Testing after 5 cycles
  Pressure Cycling Shear Bond
• Cure specimens for 7 days at 80°F.
• Apply 5,000 psi hydraulic pressure to the
  inner pipe and maintain for 10 minutes.
• Release the pressure and wait 10 minutes.
• Repeat the cycle four times.
• Perform the shear bond test.
                 Shear Bonds
System    Type 1    Foam      Beads     Latex
Base P    1194      127/98    109/78    ----
Base S    198       233       143       223
Temp P    165       299/215   191/269   ----
Temp S    72        7         56        149
Press P   194/106   276/228   294/170   -----
Press S   23        22 C      23 C      11
         New Temperature Cycling
               Procedures
• Samples are then cured at 80°F for 7 days.
• Samples are then temperature cycled from 80°F to
  180°F to 80°F as described below:
   – Internal pipe heated to test temperature in 8 hours
   – Held static for one hour
   – Cooled to 80 F
        Annular Seal Testing
• Three molds are used to prepare samples.
  – Soft Formation—a soft gel mold provides a
    semi-restricting force on the outside of the
    core during curing
  – Intermediate Formation—a 3-in. diameter
    Schedule 40 PVC pipe contains the slurry
  – Hard Formation—a 3-in. diameter Schedule
    40 steel pipe provides a restricting force
    outside of the core during curing
           Annular Seal Test Configurations




Steel or PVC
Pipe


                                                         Plastisol
                                                         Sleeve




                 Simulated hard or      Simulated soft
               intermediate formation     formation
     Annular Seal Test Procedure
• Mix cements and pour into molds.
• Cure for 7 days in an 80°F water bath.
• Apply hydraulic pressure to the inner pipe or heat
  the inner pipe to simulate thermal/pressure
  cycling.
• Test flow after each specified cycle
• Test three specimens from each test
  composition/formation scenario.
   – Different procedures are used to test each of the mold
     types.
Soft Annular Seal Test Model
      N2 Out




                       Seal for
                       Confining
                       Pressure


                       Confining
                       Pressure


                       Rubber
                       Sleeve




               N2 In
            Annular Seal Test Results
 Annular Seal Test      Class A         Foamed                       Bead

    Initial Flow,       0 Flow           0 Flow                     0 Flow
        Hard
    Initial Flow,       0 Flow           0.5 md                     0 Flow
         Soft
   Temp-Cycled,         0 Flow           0 Flow                     0 Flow
      Hard
   Temp-Cycled,
    Intermediate
   Temp-Cycled,         0 Flow    123 md/(2200 md)                   43 md
      Soft                                                   (cracked during cycling)

  Pressure-Cycled,      0 Flow           0 Flow                     0 Flow
        Hard
Pressure-Cycled, Soft   27 md            0.19 md                     3 md
                                  (cracked during cycling)
          Pipe in Pipe Testing
•   10’ models of 2” pipe
•   Pressurized to 1000 psi
•   Cured for 8 days
•   100 to 500 psi
•   Measured Flow rates for months
            Future Work
• Complete Annular Seal and Shear bond
  testing
• Complete Anelastic Strain Testing
• Begin Decision Tree

								
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