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