Studies in Abnormal Pressures 38

Studies in Abnormal Pressures......Page 4
Copyright Page......Page 5
Preface......Page 6
Walter H. Fertl......Page 8
Foreword......Page 10
List of Contributors......Page 12
Contents......Page 14
1.1 Introduction......Page 20
1.2 Abnormal pressure occurrences in the Middle East......Page 21
1.3 Abnormal pressure occurrences in Europe......Page 22
1.4 Abnormal pressure occurrences in Russia, Azerbaijan, and Kazakhstan......Page 23
1.5 Abnormal pressure occurrences in Africa......Page 24
1.6 Abnormal pressure occurrences in the People’s Republic of China......Page 25
1.7 Abnormal pressure occurrences in South-East Asia, Australia, New Zealand and the Indonesian Archipelago......Page 27
1.9 Abnormal pressure occurrences in South America......Page 30
1.10 Abnormal pressure occurrences in North America......Page 31
Acknowledgements......Page 34
References......Page 35
2.1 History......Page 38
2.2 Regressive sequences......Page 47
2.3 Rift basins......Page 58
2.4 Synthesis......Page 65
References......Page 66
3.1 Properties of fluids and the rocks that contain them......Page 70
3.2 Liquids in motion through porous rocks......Page 82
3.3. Pore pressures......Page 88
3.4 Possible causes of abnormally high pore pressures......Page 96
3.5 Sliding......Page 103
References......Page 107
4.1 Introduction......Page 112
4.2 P/Z plots and drive mechanism......Page 113
4.3 Abnormally pressured depletion drive reservoirs......Page 115
4.4 Abnormally pressured water drive reservoirs......Page 122
References......Page 124
5.1 Introduction......Page 126
5.2 Composition of subsurface brines......Page 130
5.3 Fluid chemistry compaction models......Page 155
5.4 Summary and conclusions......Page 166
References......Page 168
6.1 Introduction......Page 174
6.2 Velocity......Page 175
6.3 Seismic data acquisition, processing and interpretation......Page 177
6.4 Pressure calibration and pre-drill geopressure detection......Page 192
6.6 Summary......Page 203
References......Page 204
7.1 Introduction......Page 206
7.2 Acoustic methods......Page 207
7.3 Density methods......Page 218
7.4 Conventional neutron methods......Page 219
7.5 Resistivity methods......Page 221
7.6 Conductivity methods......Page 224
7.7 SP method......Page 229
7.8 The shale formation factor method......Page 235
7.9 Magnetic resonance method......Page 237
7.10 Method utilizing downhole gravity measurements......Page 238
7.11 Pulsed neutron method......Page 239
7.13 Limitations of wireline methods......Page 243
7.14 Conclusions......Page 253
References......Page 254
8.2 Predicting ahead of the bit with VSP data......Page 260
8.3 The inverse VSP concept......Page 263
8.5 The drill bit source......Page 264
8.6 Predict-ahead data examples......Page 266
References......Page 269
9.1 Introduction......Page 270
9.2 Telemetry techniques......Page 271
9.3 MWD sensors......Page 278
9.4 Abnormal pressure detection with MWD......Page 291
9.5 Service company comparison......Page 294
References......Page 296
10.1 Introduction......Page 300
10.2 Prevention of shallow gas flows......Page 301
10.3 Developing contingency plans......Page 304
10.4 Diverter design......Page 306
10.5 Exit velocity calculation......Page 307
10.6 Flowing pressure gradient calculation......Page 310
10.7 Formation productivity......Page 312
10.8 Equilibrium gas flow rate......Page 315
10.10 Working pressure of diverter components......Page 316
10.12 Rate of erosion......Page 319
10.14 Control system......Page 326
10.15 Design considerations for dynamic kill......Page 327
10.16 Diverter operation......Page 330
10.17 Special considerations for floating drilling vessels......Page 331
10.18 Recommendations......Page 333
Appendix — Nomenclature......Page 334
References......Page 335
11.2 Blowout flowrate......Page 338
11.3 Blowout control......Page 341
11.4 Directional planning and trajectory design......Page 345
11.5 Directional surveying......Page 346
11.6 Blowout well distance from relief well......Page 349
11.7 Blowout examples......Page 354
11.8 Conclusions......Page 358
References......Page 359
12.1 Introduction......Page 362
12.3 Abnormally high pressure from hydrocarbon generation......Page 364
12.4 Distribution and character of overpressure......Page 366
12.5 Summary and conclusions......Page 388
References......Page 391
13.1 Introduction......Page 396
13.2 Reservoir communication......Page 397
13.3 Associated gas......Page 398
13.4 Non-associated gas......Page 401
13.5 Conclusions......Page 407
References......Page 408
14.2 Top of abnormal pressure......Page 410
14.3 Hydrocarbon distribution versus top of abnormal pressure......Page 411
14.4 Hydrocarbon distribution decreases with increased pressure......Page 414
14.5 Hydrocarbon distribution versus depth and temperature......Page 422
14.6 Hydrocarbon distribution decreases with increased temperature......Page 423
14.7 Disappearance of hydrocarbons in high-pressure/high-temperature environments......Page 425
14.8 Vertical fluid migration and hydrocarbon concentration......Page 428
14.9 Probable source of Upper Tertiary hydrocarbons......Page 436
14.11 Maximum hydrocarbon window......Page 438
14.12 Probability of exploration/exploitation enhancement with MHW technique......Page 439
14.13 Probability of exploitation enhancement with SRR technique......Page 444
14.14 Future exploration and development potential......Page 445
References......Page 446
Glossary......Page 448
Practical Conversion Factors......Page 462
Subject index......Page 466