Page 13 - Fundamentals of Gas Shale Reservoirs

CONTENTS xi
14 Resource estimation for Shale Gas Reservoirs 301
14.1 Introduction, 301
14.1.1 Unique Properties of Shale, 301
14.1.2 Petroleum Resources Management System (PRMS), 301
14.1.3 Energy Information Administration’s Classification System, 301
14.1.4 Reserves Estimate Methodology for Unconventional Gas Reservoirs, 302
14.1.5 Monte Carlo Probabilistic Approach, 302
14.1.6 Analytical Models, 303
14.1.7 Economic Analysis, 303
14.1.8 Region‐Level World Shale Gas Resource Assessments, 304
14.1.9 Shale Gas OGIP Assessment in North America, 305
14.1.10 Recent Shale Gas Production and Activity Trends, 306
14.1.11 Drilling, Stimulation, and Completion Methods in Shale Gas Reservoirs, 308
14.2 Methodology, 309
14.3 Resource Evaluation of Shale Gas Plays, 310
14.3.1 Reservoir Model, 310
14.3.2 Well Spacing Determination, 310
14.3.3 Reservoir Parameters Sensitivity Analysis, 311
14.3.4 Reservoir Parameters, 312
14.3.5 Model Verification, 312
14.3.6 Resource Assessment, 313
14.3.7 Reserve Evaluation, 318
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
15.1.1 Molecular Dynamics Simulation, 325
15.1.2 Major Challenges in Shale Gas Research, 326
15.1.3 MS of Gas Adsorption, 326
15.1.4 Methodology and Workflow of Molecular Simulation, 327
15.1.5 Simulation Algorithms and Software, 327
15.2 MS of Gas Adsorption on Minerals, 327
15.2.1 MD Simulation of Gas Adsorption on Quartz, 328
15.2.2 Molecular Dynamic Simulation of Gas Adsorption on Wyoming‐Type Montmorillonite, 330
15.2.3 MD Simulation of Gas Adsorption on Zeolite, 332
15.2.4 MD Simulation of Gas Adsorption on Coal, 334
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
16.4.1 Sample Expansion, 343
16.4.2 Depositional Lamination, 346
16.4.3 Chemical Osmosis, 346
16.4.4 Water Film and Salt Crystals, 348
16.4.5 Water Adsorption (Clay Swelling), 348
16.4.6 Connectivity of Hydrophobic and Hydrophilic Pore Networks, 349
16.4.7 Effect of Polymer and Surfactant, 351