Long Term Integrity of Cement Systems

1
Long Term Integrity of Cement Systems

• Oct 4, 2002

2
Agenda

• Participants/Financials
• Project Focus/Management
• Project Tasks
• Summary Action Items

3
Participants

• Commitments
• MMS, Petrobas, Unocal, BP, ExxonMobil
• Saudi Aramco, ONGC, Conoco, AGIP
• DOE, Anadarko, PDVSA
• Potentials
• ChevronTexaco, Stat Oil
• What about Service Companies ?

4
Financials

• Commitments - 50k each
• 600k 12 Companies
• Potential additional 100 to 150k
• Project Timing 18 months

5
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

6
Project Communications

• Steering Committee Voting Members
• Meeting notes/ voting privileges
• Short Monthly reports - Email
• Technical
• Quarterly Progress Report/Meeting
• Feb 2003

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Project Objective

• Determine the cement system properties that
  effects 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

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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

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Testing Program

• Deep Water/All Conditions in Gulf of Mexico
• Cement Slurries
• Class A
• Foamed Cement
• Bead Cement
• Class H
• Latex Cement
• Other modifications of above

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Conventional Tests

• Conditions 45 F BHST, 65 F BHCT
• Tests
• Thickening Time - 4 to 6 hours
• Free Water lt 1
• Compressive Strength (24hr and 14 days)
• Fluid Loss, SGS when appropriate

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Thickening Time Free Water
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Mechanical Integrity Issues

• Flow of Fluids
• Around the Cement
• Bonding, Microannulus, Deformation
• Through the matrix of the Cement
• Cracking, Permeability changes
• Stress
• Pressure, Temperature, Pipe Buckling, Formation
  Compaction
• Cycling Conditions

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Mechanical Properties

• Rock mechanics/Acoustic Measurements
• Tensile Strength/Youngs Modulus (T)
• Youngs Modulus/Poissons Ratio

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Tensile Strength

• Brazilian Test Method
• Tensile Strength Youngs Modules
• Maximum Yield

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Tensile Strength and Youngs Modulus
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Youngs Modules

• Compressional Tests
• Confining Loads Defined by 0psi break
• Base line 14 day cure
• Acoustic Data
• Poissons Ratio

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Comparison of Compressive Strength
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Type 1 CYM
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12 ppg Foam CYM
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12 ppg Bead CYM
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Latex CYM
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Hydrostatic Cycles
10 ppg foam
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Acoustic Measurements

• Chandlers New Mechanical Properties Device

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Chandler Device
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Rock Mechanic Data
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Performance Tests

• Shear Bond Measurements (Cycling conditions)
• Soft formations
• Hard Formations
• Annular Seal/Hassler Sleeve (Cycling Conditions)
• Soft Formations
• Hard Formations

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Temperature Cycling Procedures

• Samples are then cured at 45F for 14 days.
• Samples are then temperature cycled from 45F to
  180F to 45F as described below
• Samples are placed in a 96F water bath for 1
  hour.
• Samples are placed in a 180F water bath for 4
  hours.
• Samples are placed in a 96F water bath for 1
  hour.
• Samples are placed back in a 45F water bath.
• The samples are cycled once per day during the
  cycling period.

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Shear Bonds
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Annular Seal Test Configurations
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Annular Seal Tests
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Annular Seal Test Model
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Pipe in Pipe Testing

• No fluid external to the cement
• 6 flanged models
• 6 flanged model with pressure (200 psi)
• 5 flanged model vacuum system
• 5 flanged model with pressure (200 psi)
• Conclusion tight seal to gas

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Mathematical Model

• Presented by
• University of Houston

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Future Work
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YM Hydrostatic
10 ppg foam
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YM (Hyd Cycle)
10 ppg foam
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YM Cycle
10 ppg foam