Petroleum Related Rock Mechanics (eBook)

Front Cover 1
Petroleum Related Rock Mechanics 4
Copyright Page 5
Table of Contents 10
Chapter 1. Elasticity 16
1.1 Linear elasticity 16
1.2 Non-linear elasticity 42
1.3 Poroelasticity 47
1.4 Time-dependent effects 54
Chapter 2. Failure mechanics 62
2.1 Basic concepts 62
2.2 The failure surface 64
2.3 Shear farlure - Mohr’s hypothesis 66
2.4 Failure criteria which depend on the intermediate stress 74
2.5 Representation of experimental data 76
2.6 Extension tests 77
2.7 Post-failure behaviour 79
2.8 The theory of plasticity 81
2.9 Soil mechanics 88
2.10 Failure mechanics of saturated rocks 97
2.11 Anisotropy and rock mechanical failure 98
Chapter 3. Some geological aspects of rock mechanics 104
3.1 Underground stresses 104
3.2 Pore pressure 114
3.3 Rock mechanical properties 117
Chapter 4. Stresses around boreholes, and borehole failure criteria 124
4.1 Stresses around boreholes 124
4.2 Borehole failure criteria 136
4.3 Beyond failure initiation 142
Chapter 5. Acoustic wave propagation in rocks 150
5.1 The wave equation 150
5.2 P- and S-waves 152
5.3 Sound velocities in rocks 154
5.4 Acoustic attenuation in rocks 157
5.5 Biot’s theory of acoustic wave propagation 161
5.6 Acoustic anisotropy 166
5.7 Rock mechanics and rock acoustics 170
Chapter 6. Micromechanical models 176
6.1 Grain pack models 176
6.2 Effective medium theories of rocks containing cracks 180
6.3 Fractured rocks 189
Chapter 7. Mechanical properties from laboratory analysis 200
7.1 Core samples for rock mechanical laboratory analysis 201
7.2 Laboratory Equipment 205
7.3 Rock mechanical test procedures 209
7.4 Index Tests 216
7.5 Acoustic measurements 219
Chapter 8. Mechanical properties from field data 224
8.1 Estimation of elastic parameters 224
8.2 Estimation of in situ stresses 240
8.3 Estimation of strength parameters 246
Chapter 9. Stability during drilling 252
9.1 Unstable boreholes - reasons and consequences 253
9.2 The principle of a stability analysis 255
9.3 Calculation of minimum mudweight required to prevent borehole collapse 256
9.4 Calculation of maximum mudweight before fracturing 258
9.5 Example Calculation 259
9.6 Evaluation of the method and the results 261
9.7 Other aspects of practical importance 264
Chapter 10. Sand prediction 272
10.1 What is sand production? 272
10.2 How can sand production be controlled? 273
10.3 Mechanisms for sand production 274
10.4 What is sand prediction'? 275
10.5 Examples of problems to be considered 275
10.6 Modelling for sand prediction 277
Chapter 11. Fracturing 284
11.1 Conditions for tensile failure 285
11.2 Orientation and confinement of fractures 287
11.3 Fracturing pressures 290
11.4 Formation break-down pressures 292
11.5 Determination of fracturing pressures from minifrac tests 294
11.6 Pressures during frac jobs 296
11.7 Fracture gradients in drilling 297
Chapter 12. Reservoir compaction. Subsidence and well problems 302
12.1 Elastic modelling of compaction and subsidence 304
12.2 Consolidation theory 315
12.3 A Consolidation type subsidence model 320
12.4 Laboratory testing for compaction predictions 326
12.5 Numerical modelling of compaction and subsidence 327
12.6 Well Problems associated with compaction 329
Appendix A 334
Appendix B 340
Symbols 342
Index 346