Description
Contributors xv Preface xvii 1 Gas Shale: Global Significance Distribution and Challenges 1 1.1 Introduction 1 1.2 Shale Gas Overview 1 1.3 The Significance of Shale Gas 4 1.4 Global Shale Gas Resources 5 1.5 Global Resource Data 7 1.6 Data Assessment 11 1.7 Industry Challenges 13 1.8 Discussion 14 1.9 Conclusions 15 Appendix A.1 Global Shale Gas Resource Data 16 2 Organic Matter?]Rich Shale Depositional Environments 21 2.1 Introduction 21 2.2 Processes Behind the Deposition of Organic Matter?]Rich Shale 23 2.3 Stratigraphic Distribution of Organic Matter?]Rich Shales 25 2.4 Geographic Distribution of Organic Matter?]Rich Shales 27 2.5 Organic Matter?]Rich Shale Depositional Environments 34 2.6 Conclusion 39 3 Geochemical Assessment of Unconventional Shale Gas Resource Systems 47 3.1 Introduction 47 3.2 Objective and Background 49 3.3 Kerogen Quantity and Quality 49 3.4 Sample Type and Quality 51 3.5 Kerogen Type and Compositional Yields 52 3.6 Thermal Maturity 54 3.7 Organoporosity Development 55 3.8 Gas Contents 57 3.9 Expulsion-Retention of Petroleum 57 3.10 Secondary (Petroleum) Cracking 58 3.11 Upper Maturity Limit for Shale Gas 58 3.12 Gas Composition and Carbon Isotopes 59 3.13 Additional Geochemical Analyses for Shale Gas Resource System Evaluation 61 3.14 Oil and Condensate with Shale Gas 63 3.15 Major Shale Gas Resource Systems 64 3.16 Conclusions 65 4 Sequence Stratigraphy of Unconventional Resource Shales 71 4.1 Introduction 71 4.2 General Sequence Stratigraphic Model for Unconventional Resource Shales 71 4.3 Ages of Sea?]Level Cycles 72 4.4 Water Depth of Mud Transport and Deposition 73 4.5 Criteria to Identify Sequences and Systems Tracts 74 4.6 Paleozoic Resource Shale Examples 74 4.7 Mesozoic Resource Shale Examples 80 4.8 Cenozoic Resource Shale Example 83 4.9 Conclusions 84 4.10 Applications 84 5 Pore Geometry in Gas Shale Reservoirs 89 5.1 Introduction 89 5.2 Samples Characteristics 90 5.3 Experimental Methodology 91 5.4 Advantages and Disadvantages of Experimental PSD Methods 95 5.5 Permeability Measurement 95 5.6 Results 96 5.7 Discussion 103 5.8 Conclusions 112 Appendix 5.A XRD Results 114 6 Petrophysical Evaluation of Gas Shale Reservoirs 117 6.1 Introduction 117 6.2 Key Properties for Gas Shale Evaluation 117 6.3 Petrophysical Measurements of Gas Shale Reservoirs 121 6.4 Well Log Analysis of Gas Shale Reservoirs 125 7 Pore Pressure Prediction for Shale Formations Using well Log Data 139 7.1 Introduction 139 7.2 Overpressure-Generating Mechanisms 140 7.3 Overpressure Estimation Methods 146 7.4 The Role of Tectonic Activities on Pore Pressure In Shales 151 7.5 Discussion 160 7.6 Conclusions 165 8 Geomechanics of Gas Shales 169 8.1 Introduction 169 8.2 Mechanical Properties of Gas Shale Reservoirs 170 8.3 Anisotropy 175 8.4 Wellbore Instability in Gas Shale Reservoirs 176 9 Rock Physics Analysis of Shale Reservoirs 191 9.1 Introduction 191 9.2 Laboratory Measurements on Shales: Available Datasets 192 9.3 Organic Matter Effects on Elastic Properties 192 9.4 Partial Saturation Effects 195 9.5 Maturity Effects 197 9.6 Seismic Response of Orss 201 9.7 Conclusions 203 10 Passive Seismic Methods for Unconventional Resource Development 207 10.1 Introduction 207 10.2 Geomechanics and Natural Fracture Basics for Application to Hydraulic Fracturing 209 10.3 Seismic Phenomena 213 10.4 Microseismic Downhole Monitoring 216 10.5 Monitoring Passive Seismic Emissions with Surface and Shallow Buried Arrays 222 10.6 Integrating Interpreting and Using Passive Seismic Data 235 10.7 Conclusions 241 11 Gas Transport Processes in Shale 245 11.1 Introduction 245 11.2 Detection of Nanopores in Shale Samples 247 11.3 Gas Flow in Micropores and Nanopores 248 11.4 Gas Flow in a Network of Pores in Shale 251 11.5 Gas Sorption in Shale 252 11.6 Diffusion in Bulk Kerogen 253 11.7 Measurement of Gas Molecular Diffusion into Kerogen 255 11.8 Pulse?]Decay Permeability Measurement Test 256 11.9 Crushed Sample Test 260 11.10 Canister Desorption Test 262 12 A Review of the Critical Issues Surrounding the Simulation of Transport and Storage in Shale Reservoirs 267 12.1 Introduction 267 12.2 Microgeometry of Organic?]Rich Shale Reservoirs 268 12.3 Gas Storage Mechanisms 269 12.4 Fluid Transport 270 12.5 Capillary Pressure Relaxation to Equilibrium State and Deposition of Stimulation Water 273 12.6 Characterization of Fluid Behavior and Equations of State Valid for Nanoporous Media 274 12.7 Upscaling Heterogeneous Shale?]Gas Reservoirs into Large Homogenized Simulation Grid Blocks 277 12.8 Final Remarks 280 13 Performance Analysis of Unconventional Shale Reservoirs 283 13.1 Introduction 283 13.2 Shale Reservoir Production 283 13.3 Flow Rate Decline Analysis 284 13.4 Flow Rate and Pressure Transient Analysis in Unconventional Reservoirs 288 13.5 Reservoir Modeling and Simulation 292 13.6 Specialty Short-Term Tests 295 13.7 Enhanced Oil Recovery 297 13.8 Conclusion 298 14 Resource Estimation for Shale Gas Reservoirs 301 14.1 Introduction 301 14.2 Methodology 309 14.3 Resource Evaluation of Shale Gas Plays 310 14.4 Discussion 320 15 Molecular Simulation of Gas Adsorption in Minerals and Coal: Implications for Gas Occurrence in Shale Gas Reservoirs 325 15.1 Introduction 325 15.2 MS of Gas Adsorption on Minerals 327 15.3 Conclusions 337 16 Wettability of Gas Shale Reservoirs 341 16.1 Introduction 341 16.2 Wettability 341 16.3 Imbibition in Gas Shales 342 16.4 Factors Influencing Water Imbibition in Shales 343 16.5 Quantitative Interpretation of Imbibition Data 352 16.6 Estimation of Brine Imbibition at the Field Scale 354 16.7 Initial Water Saturation in Gas Shales 356 16.8 Conclusions 356 17 Gas Shale Challenges Over The Asset Life Cycle 361 17.1 Introduction 361 17.2 The Asset Life Cycle 361 17.3 Exploration Phase Discussion 362 17.4 Appraisal Phase Discussion 365 17.5 Development Phase Discussion 367 17.6 Production Phase Discussion 375 17.7 Rejuvenation Phase Discussion 376 17.8 Conclusions–Recommended Practices 377 18 Gas Shale Environmental Issues and Challenges 381 18.1 Overview 381 18.2 Water Use 381 18.3 The Disposal and Reuse of Fracking Wastewater 382 18.4 Groundwater Contamination 384 18.5 Methane Emissions 386 18.6 Other Air Emissions 387 18.7 Social Impacts on Shale Gas Communities 388 18.8 Induced Seismicity: Wastewater Injection and Earthquakes 388 18.9 Regulatory Developments 389 18.10 Disclosure of Fracking Chemicals 389 18.11 At the Federal Government Level 390 18.12 Conclusion 391 Index 397
