Report AL MMS June 2003

Long Term Integrity of Cement Systems: 

Long Term Integrity of Cement Systems June 19, 2003

Agenda: 

Agenda Participants/Financials Project Focus/Management Project Tasks Summary Action Items API Test Data Seal Tite Test Results

Participants: 

Participants Commitments MMS, Petrobas, Unocal, BP, ExxonMobil Saudi Aramco, ONGC, Conoco, AGIP DOE, *PDVSA, HES, Dominion Potentials Marathon, Stat Oil, Devon,

Financials: 

Financials Commitments - $50k each $650k 13 Companies Potential additional $100 to 150k To date - $450 Project Timing – 18 months

Management of Project: 

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: 

Project Communications Steering Committee – Voting Members Meeting notes/ voting privileges Quarterly Progress Report/Meeting June 2003 October 2003

Project Objective: 

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: 

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: 

Testing Program Deep Water/All Conditions Cement Slurries Class A Foamed Cement Bead Cement Class H Latex Cement Fibers, Expansion additives

Performance Issues: 

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: 

Testing Program Cement design performance Mathematical modeling Mechanical properties Performance

Cement Design Performance: 

Cement Design Performance Standard cement design testing Thickening time Compressive strength Rheology Free water

Mathematical Modeling: 

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: 

Mechanical Properties Tensile strength Young’s modulus Poisson's ratio Hydrostatic pressure cycling Fatigue/anelastic strain

Tensile Strength: 

Tensile Strength Brazilian Test Method Tensile Strength Young’s Modulus Maximum Yield

Testing Device: 

Testing Device Samples are oriented on side for tensile strength tests. Force is applied by constant displacement of bottom plate.

Slide17: 

Tensile Strength and Young’s Modulus

C Young’s Modulus: 

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: 

Young’s Modulus Results

Correction: 

Correction Recently discovered correction factor accounts for instrument strain Next report will have corrected information

Poisson’s Ratio Results: 

Poisson’s Ratio Results Variable depending on: Stress Rate Slurry Type Air Entrainment

Poisson Ratio, 50 psi 250 psi/min: 

Poisson Ratio, 50 psi 250 psi/min

Strain Amounts/Cycling: 

Strain Amounts/Cycling

Acoustic Measurements: 

Acoustic Measurements Chandler’s New Mechanical Properties Device

Anelastic Strain Procedure: 

Anelastic Strain Procedure Measure failure stress. Apply stress equal to 25%, 50%, or 75% of failure. Measure deformation.

Anelastic Strain Results: 

Anelastic Strain Results Bead Slurry, Confining Pressure = 0 psi, 250 psi/min, cycle 25% of failure stress

Performance Tests: 

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: 

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. Simulated Hard or Intermediate Formation

Old Temperature Cycling Procedure: 

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: 

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: 

Shear Bonds

New Temperature Cycling Procedures: 

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: 

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: 

Annular Seal Test Configurations

Annular Seal Test Procedure: 

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: 

Soft Annular Seal Test Model

Annular Seal Test Results: 

Annular Seal Test Results

Pipe in Pipe Testing: 

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: 

Future Work Complete Annular Seal and Shear bond testing Complete Anelastic Strain Testing Begin Decision Tree