Formation Testing –
Supercharge, Pressure Testing and Contamination Models
December 2018
by
Wilson C. Chin, Ph.D., M.I.T.
Table of Contents
Preface vi
Acknowledgements viii
1. Formation Testing – Strategies, Capabilities and Solutions 1
1.1 Development Perspectives 1
1.2 Basic Forward and Inverse Models 4
1.3 Supercharge Forward and Inverse Models 14
1.4 Multiple Drawdown and Buildup Inverse Models 20
1.5 Multiphase Cleaning and Supercharge Model 24
1.6 System Integration and Closing Remarks 29
1.7 References 30
2. Supercharging – Forward Models and Inverse Solutions 31
2.1 Supercharge and Math Model Development 31
2.2 Supercharge Pressure and Ultimate Decay 34
2.3 United States Patent 7,243,537 B2 37
2.4 Forward and Inverse Models with Supercharging –
Drawdown-Only and Drawdown-Buildup Applications
and Illustrative Examples 69
2.4.1 General Ideas in Formation Testing
Formulations 69
2.4.2 Mathematical Formulation 73
2.5 Drawdown Only Applications 78
2.5.1 Example DD-1, High Overbalance 78
2.5.2 Example DD-2, High Overbalance 84
2.5.3 Example DD-3, High Overbalance 88
2.5.4 Example DD-4, Qualitative Pressure Trends 92
2.5.5 Example DD-5, Qualitative Pressure Trends 95
2.5.6 Example DD-6, "Drawdown-Only" Data with Multiple
Inverse Scenarios for 1 md/cp Application 97
2.5.7 Example DD-7, "Drawdown-Only" Data with Multiple
Inverse Scenarios for 0.1 md/cp Application 102
2.6 Drawdown – Buildup Applications 107
2.6.1 Example DDBU-1, Drawdown-Buildup, High
Overbalance 107
2.6.2 Example DDBU-2, Drawdown-Buildup, High
Overbalance 111
2.6.3 Example DDBU-3, Drawdown-Buildup, High
Overbalance 114
2.6.4 Example DDBU-4, Drawdown-buildup, 1 md/cp
Calculations 118
2.6.5 Example DDBU-5, Drawdown-buildup, 0.1 md/cp
Calculations 122
2.7 Supercharged Anisotropic Flow Simulation Model 127
2.8 References 131
3. Pressure Transient Analysis – Multirate Drawdown and
Buildup 132
3.1 Multirate Drawdown and Buildup Applications 133
3.1.1 Monitoring, Testing, Treatment and Retest 134
3.1.2 Hydrate Characterization and Production 138
3.2 Detailed Validations with Exact Solutions 142
3.2.1 Validation of PTA-App-01 Inverse Model 144
3.2.2 Validation of PTA-App-02 Inverse Model 148
3.2.3 Validation of PTA-App-03 Inverse Model 156
3.2.4 Validation of PTA-App-04 Inverse Model 163
3.2.5 Validation of PTA-App-05 Inverse Model 172
3.2.6 Validation of PTA-App-06 Inverse Model 177
3.2.7 Validation of PTA-App-07 Inverse Model 182
3.2.8 Validation of PTA-App-08 Inverse Model 187
3.2.9 Validation of PTA-App-09 Inverse Model 192
3.2.10 Validation of PTA-App-10 Inverse Model 197
3.2.11 Validation of PTA-App-11 Inverse Model 202
3.3 References 219
4. Practical Applications and Examples 221
4.1 Review Objectives 221
4.2 Practical Applications and Examples 222
4.2.1 Isotropic Medium Pressure Testing 222
4.2.1.1 Steady-state method 222
4.2.1.2 Drawdown-buildup method 226
4.2.1.3 Drawdown only method 230
4.2.2 Anisotropic Media Pressure Testing
(Using FT-01) 232
4.2.3 Supercharge Effects in Drawdown-Buildup 240
4.2.4 Supercharge Mechanics in Detail –
Reservoir Fluid More Viscous Than Mud 250
4.2.5 Supercharge Mechanics in Detail –
Reservoir Fluid Less Viscous Than Mud 261
4.2.6 Supercharge Mechanics in Detail –
Reservoir Fluid Viscosity Equals Mud
Viscosity 264
4.2.7 Perfectly Balanced Well, Mechanics in Detail –
Reservoir Fluid Viscosity Equals Mud
Viscosity 266
4.2.8 Underbalance Mechanics in Detail –
Reservoir Fluid Viscosity Equals Mud
Viscosity 268
4.2.9 Comparing Overbalance vs Underbalance
Pressures for Same Reservoir and Tool Pumping
Conditions 270
4.2.10 Consequences of Non-Performing Pump Piston 284
4.2.11 Batch Processing Using FT-00 291
4.2.12 Depth of Investigation Using FT-00 DOI
Function 296
4.2.13 History Matching Using FT-06 Batch Mode 306
4.2.13.1 Operating FT-06 batch simulator 308
4.2.13.2 Source code documentation
(color coded) 313
4.2.13.3 A final example – concise operational
summary 328
4.2.14 Gas Pumping 334
4.2.14.1 Several field notes 334
4.2.14.2 Review of steady-state direct and inverse
methods 335
4.2.14.3 Transient gas calculations 338
4.3 References 342
5. Best Practices and Closing Remarks 343
5.1 Best Practices 343
5.2 Recommended Reading 351
Cumulative References 352
Index 363
About the Author 369