Foreword xi
Introduction 1
A Brief History of S. A. Holditch & Associates Inc. 1
Purpose of this Book 1
Part 1 — Unconventional Gas Resources
Chapter 1 – Introduction to Unconventional Gas Reservoirs 3
1.1 Definition of Unconventional Gas 3
1.2 The Resource Triangle 4
1.3 Geographical Information on Unconventional Gas 4
1.4 Global Gas Resources 4
1.5 Coal Seams 6
1.6 Shale Gas 7
1.7 Nomenclature 7
1.8 References 7
Chapter 2 – Tight Gas Reservoirs 9
2.1 Tight Gas in the US 9
2.2 Geologic Considerations 10
2.3 Reservoir Considerations 12
2.4 Drilling and Completion Considerations 12
2.5 Formation Evaluation 12
2.6 Formation Mechanical Properties 18
2.7 Estimating Permeability 18
2.8 Statistical Correlations 22
2.9 Developing Databases 28
2.10 Well Construction 30
2.11 Post-Fracturing Reservoir Evaluation Methods 34
2.12 Estimating Reserves in Tight Gas Reservoirs 36
2.13 Nomenclature 39
2.14 References 39
Chapter 3 – Coalbed Methane 43
3.1 Introduction 43
3.2 Evolution of CBM Engineering Practices 44
3.3 Overview of Coalbed Gas Systems 46
3.4 CBM Reservoir Properties 48
3.5 CBM Production Practices 51
3.6 Summary of CBM 57
3.7 References 57
Chapter 4 – Shale Gas 59
4.1 Introduction 59
4.2 Gas Shale Properties 59
4.3 Overview of Completion Techniques 78
4.4 Eagle Ford Shale 82
4.5 Summary 86
4.6 References 87
Part 2 — Tight Gas Sands Engineering
Chapter 5 – Reservoir Characterization 91
5.1 Geologic Considerations 91
5.2 Logging and Log Analyses 102
5.3 Coring and Core Analysis 122
5.4 Correlations 137
5.5 Nomenclature 156
5.6 References 158
Chapter 6 – Prestimulation Well Testing 161
6.1 Diffusivity Equation 161
6.2 Radial Flow 162
6.3 Log-Log Type Curve Analysis 175
6.4 Manual Parameter Estimation Using the Log-Log Diagnostic Plot 183
6.5 Flow-Regime Identification Using the Log-Log Diagnostic Plot 186
6.6 Boundary Effects 188
6.7 Pseudosteady-State Flow (PSSF) 202
6.8 Naturally Fractured Reservoirs 204
6.9 Pressure-Dependent Rock Properties 211
6.10 Coalbed Methane and Naturally Fractured Shale 214
6.11 Flow Tests in Low-Permeability Gas Reservoirs 214
6.12 Summary 216
6.13 Nomenclature 217
6.14 References 218
Appendix 6.A 220
6.A.1 Summary of Equations in Terms of Pressure, Adjusted Pressure, Pressure Squared, and Pseudopressure 220
Chapter 7 – Post-Fracture Treatment Well Testing 225
7.1 Hydraulically Fractured Well Models 225
7.2 Flow Regimes in Hydraulically Fractured Wells 226
7.3 Straight-Line Analysis Methods 231
7.4 Log-Log Type Curve Analysis 247
7.5 Parameter Estimation Using the Log-Log Diagnostic Plot 250
7.6 Estimating Fracture Properties from Flow Regime Limits 254
7.7 Area of Investigation 256
7.8 Fracture Damage 257
7.9 Non-Darcy Effects 258
7.10 Effect of Permeability Anisotropy on Estimated Fracture Half-Length 259
7.11 Summary 260
7.12 Nomenclature 261
7.13 References 262
Appendix 7.A 263
7.A.1 Summary of Equations in Terms of Pressure, Adjusted Pressure, Pressure Squared, and Pseudopressure 263
Chapter 8 – Rate Transient Analysis 267
8.1 Introduction 267
8.2 Conventional Decline-Curve Analysis 268
8.3 Rate Type Curves for a Well Produced at Constant Flowing Bottomhole Pressure 271
8.4 Fetkovich Type Curve 273
8.5 Modifications of the Fetkovich Type Curve 280
8.6 Modifications for Pressure-Dependent Fluid and Rock Properties 283
8.7 Modifications for Variable-Rate/Variable-Pressure Production 287
8.8 Analyzing Production Data with Pressure Transient Type Curves 297
8.9 Agarwal-Gardner Type Curves 300
8.10 Extended Material Balance 304
8.11 Comparison of Results from West Virginia Gas-Well Example 305
8.12 Practical Considerations 306
8.13 Nomenclature 308
8.14 References 310
Chapter 9 – Well and Reservoir Numerical Modeling 313
9.1 Fundamentals of Finite-Difference Simulation 313
9.2 Modeling Hydraulically Fractured Well Performance 313
9.3 Modeling Fracturing-Fluid Invasion and Cleanup 314
9.4 Modeling Non-Darcy Flow and Fracture-Conductivity Reduction 320
9.5 Analyzing Post-Fracturing Flow and Buildup Data 323
9.6 Modeling Multilayer Reservoirs 329
9.7 Fieldwide Modeling of Tight Gas Reservoirs 332
9.8 Summary 334
9.9 Nomenclature 334
9.10 References 335
Chapter 10 – Drilling and Completion Design for Fracturing 337
10.1 Drilling Aspects 337
10.2 Completion Aspects 338
10.3 Casing and Wellbore Configuration 338
10.4 Cementing 338
10.5 Perforating 339
10.6 Completion Strategy 341
10.7 Treatment Diversion 342
10.8 References 343
Chapter 11 – Development Economics 345
11.1 Estimating Reserves in Unconventional Reservoirs 345
11.2 US SEC Rules on Reserves in Unconventional Resources 351
11.3 Use of Moving Domain 352
11.4 Average Recovery 357
11.5 Infill Drilling Potential 358
11.6 Well Completion Information 360
11.7 Estimating Costs To Develop Unconventional Reservoirs 361
11.8 Field Development Strategies and Economics 365
11.9 Benefits of Applying New Technology 365
11.10 Summary 367
11.11 References 367
Part 3 — Hydraulic Fracturing in Vertical Wells
Chapter 12 – Introduction to Hydraulic Fracturing 369
Chapter 13 – Selection of Candidates 371
13.1 Fundamental Requirements 371
13.2 Stimulation Selection Criteria 371
13.3 Productivity Improvement Factor (PIF) 372
13.4 Summary 374
13.5 Nomenclature 374
13.6 References 374
Chapter 14 – Fracture Initiation, Geometry, and Propagation 377
14.1 In-Situ Stresses 377
14.2 Near-Wellbore Fracture Geometry 378
14.3 Fracture Containment Considerations 383
14.4 Fracture Growth Analysis 385
14.5 Hydraulic Fracturing Models 390
14.6 Summary 394
14.7 Nomenclature 394
14.8 References 395
Chapter 15 – Data Acquisition and Core Measurements 397
15.1 Log Data 397
15.2 Fracture Mapping 397
15.3 Microfracture Testing 404
15.4 Minifracture Testing 407
15.5 Core Testing 413
15.6 Nomenclature 418
15.7 References 418
Chapter 16 – Fracturing Fluids and Additives: Properties and Selection 421
16.1 Introduction 421
16.2 Properties and Rheology of Fracturing Fluids 421
16.3 Types of Fracturing Fluids 424
16.4 Fracturing Fluid Additives 428
16.5 Fracturing Fluid Rheology 430
16.6 Measurement of Fracturing Fluid Rheology 431
16.7 Fluid-Leakoff Analysis 433
16.8 Fluid-Loss Equations 434
16.9 Nomenclature 436
16.10 References 436
Chapter 17 – Types of Fracture Propping Agents 439
17.1 Introduction 439
17.2 Commonly Used Proppants in Industry
17.3 Resin-Coated Proppants 441
17.4 Proppant Flowback Considerations 442
17.5 Nomenclature 444
17.6 References 444
Chapter 18 – Hydraulic Fracturing Treatment Design and Guidelines 445
18.1 Introduction to Treatment Design 445
18.2 Well Conditions and Parameters 446
18.3 Reservoir and Rock Parameters 446
18.4 Determination of Optimal Fracture Length and Conductivity 447
18.5 Perforating for Fracturing 450
18.6 Selecting a Fracturing Fluid 453
18.7 Selecting a Propping Agent 455
18.8 Determination of Fluid Properties 456
18.9 Fracturing Fluid Additives 457
18.10 Determining the In-Situ Stress Profile 458
18.11 Fracture Treatment Design Using a Fracture Model 458
18.12 Summary 463
18.13 Nomenclature 463
18.14 References 463
Chapter 19 – Planning and Executing a Hydraulic Fracture Treatment 467
19.1 Pretreatment Quality Control Considerations ? 467
19.2 Planning and Scheduling of Hydraulic Fracturing Treatments 468
19.3 Fracturing Fluid Preparation 468
19.4 Executing the Hydraulic Fracturing Treatment 469
19.5 Fracturing Treatment Diagnostics During the Treatment 470
19.6 Post-Treatment Reporting and Evaluation 472
19.7 Flowing Back the Treatment and Forced Closure 473
19.8 Fracturing Treatment Diversion Methods 476
19.9 Nomenclature 477
19.10 References 477
Index 479
Complimentary eBook Supplement
CASE HISTORIES OF TIGHT GAS RESERVOIR DEVELOPMENT
Chapter 1 – The GRI Staged Field Experiment 1
1.1 Summary 1
1.2 Introduction 1
1.3 Goals of the SFEs 2
1.4 Site Selection for SFE 1 3
1.5 Drilling Summary 5
1.6 Completion Summary 5
1.7 Prefracture Formation Evaluation 6
1.8 Summary of Prefracture Formation Evaluation 9
1.9 Fracture-Treatment Design and Execution 10
1.10 Fracture-Fluid Viscosity Measurements 12
1.11 Postfracture-Treatment Evaluation 13
1.12 Conclusions 16
1.13 Nomenclature 16
1.14 Acknowledgments 17
1.15 References 17
Chapter 2 – The Gas Research Institute’s Second Staged Field Experiment: A Study of Hydraulic Fracturing 19
2.1 Introduction 19
2.2 Objectives of SFE No. 2 19
2.3 Geologic Overview 20
2.4 Drilling Summary 22
2.5 Determining the Vertical Stress Profile 23
2.6 Completion Summary 25
2.7 Lower Travis Peak 26
2.8 Upper Travis Peak 30
2.9 Conclusions 33
2.10 Acknowledgments 34
2.11 References 34
Chapter 3 – Hydraulic Fracturing Research in East Texas: Third GRI Staged Field Experiment 35
3.1 Summary 35
3.2 Introduction 35
3.3 Objectives of SFE No. 3 35
3.4 Geologic Overview 36
3.5 Operations Summary 36
3.6 Formation Evaluation 38
3.7 Vertical Stress Profiling 39
3.8 Prefracture Analysis 40
3.9 Fracture Treatment Analysis 42
3.10 Postfracture Analysis 43
3.11 Conclusions 46
3.12 Nomenclature 47
3.13 Acknowledgments 47
3.14 References 47
Chapter 4 – Hydraulic Fracturing Research in the Frontier Formation Through the Gas Research Institute’s Fourth Staged Field Experiment 49
4.1 Introduction 49
4.2 Geologic Overview 50
4.3 Stratigraphic and Depositional Analysis 50
4.4 Analysis of Natural and Induced Fractures 51
4.5 Drilling Operations 51
4.6 Formation Evaluation 52
4.7 Core Analysis 52
4.8 Log Analysis 52
4.9 Vertical Stress Profiling 53
4.10 Prefracture Testing 53
4.11 Minifracture Injection Testing 54
4.12 Conclusions 58
4.13 Acknowledgment 58
4.14 References 58
Chapter 5 – Fracturing and Testing Case Study of Paludal, Tight, Lenticular Gas Sands 59
5.1 Summary 59
5.2 Introduction 59
5.3 Overview 59
5.4 MWX Site 60
5.5 Geologic and Sedimentologic Setting 60
5.6 Core and Log Analyses 60
5.7 Geophysical Surveys 62
5.8 Stress Test Data 63
5.9 Prefracture Well Test Data 63
5.10 Phase 1 Minifractures 63
5.11 Post-minifracture Cleanup and Well Tests 64
5.12 Hydraulic Fracture Design 65
5.13 Phase 2 Hydraulic Fracture Experiment 66
5.14 Post-fracture Cleanup 67
5.15 Post-fracture Well Testing 69
5.16 Final Production Tests After a Long-Term Shut-In 71
5.17 Discussion 71
5.18 Conclusions 72
5.19 Acknowledgments 72
5.20 References 72
Chapter 6 – Microseismic Monitoring of the B-Sand Hydraulic-Fracture Experiment at the DOE/GRI Multisite Project 75
6.1 Summary 75
6.2 Introduction 75
6.3 Background 76
6.4 M-Site 76
6.5 Receiver Orientation 77
6.6 Microseismic Processing 78
6.7 Fracture Diagnostic Results 79
6.8 Model Comparison 81
6.9 Discussion and Conclusions 82
6.10 Nomenclature 82
6.11 Acknowledgments 83
6.12 References 83
Chapter 7 – Successful Stimulation of Deep Wells Using High Proppant Concentrations 85
7.1 Introduction 85
7.2 Types of Stimulation 85
7.3 Problems in Fracturing Deep Formations 86
7.4 Mechanical Aspects 86
7.5 The Gel 86
7.6 The Vicksburg Formation 86
7.7 Comparison With Low-Viscosity Treatments 88
7.8 Effect on Rate and Recovery in the Vicksburg Formation 88
7.9 Results From Other Formations 89
7.10 Economics 89
7.11 Conclusions 90
7.12 Acknowledgment 90
7.13 References 90
Chapter 8 – A Case History of Massive Hydraulic Refracturing in the Tight Muddy “J” Formation 91
8.1 Abstract 91
8.2 Introduction 91
8.3 Discussion 91
8.4 Conclusions 96
8.5 References 97
Chapter 9 – Analyses of an Elmworth Hydraulic Fracture in Alberta 99
9.1 Introduction 99
9.2 Petrophysical Properties 99
9.3 Geologic Description 101
9.4 Sequence of Testing and Stimulation 101
9.5 Results 102
9.6 Mini-Fracture 104
9.7 Main Fracture Treatment 104
9.8 Testing After Main Fracture 105
9.9 Economics 107
9.10 Conclusions 107
9.11 Acknowledgments 108
9.12 References 108
Chapter 10 – Restimulation of Tight Gas Sand Wells in the Rocky Mountain Region 109
10.1 Abstract 109
10.2 Introduction 109
10.3 Candidate Selection Methodology 110
10.4 Field Test 1: Green River Basin 111
10.5 Field Test 2: Piceance Basin 117
10.6 Conclusions 119
10.7 Acknowledgments 119
10.8 Nomenclature 119
10.9 References 119
Chapter 11 – Employing Both Damage Control and Stimulation: A Way to Successful Development for Tight Gas Sandstone Reservoirs 121
11.1 Abstract 121
11.2 Introduction 121
11.3 Engineering Geological Characteristics of Tight Gas Sandstone Reservoirs 122
11.4 Damage Mechanisms of Tight Gas Sands 122
11.5 Temporary Shielding Drill-in Fluids and Its Matching Techniques 122
11.6 Application Cases of the Technology 124
11.7 Discussion and Understanding 125
11.8 Conclusions and Suggestions 126
11.9 References 127
Chapter 12 – Will the Blossoming of Unconventional Natural Gas Development in North America Be Repeated in China? 129
12.1 Abstract 129
12.2 Introduction 130
12.3 The Reasons Behind the Boom in Development 130
12.4 Unique Characteristics of Unconventional Gas Resources 131
12.5 Key Technologies 132
12.6 Resource Assessment 132
12.7 Natural Gas Resources and Consumption in China 136
12.8 The Challenges Ahead 137
12.9 Summary and Concluding Remarks 139
12.10 References 139
Chapter 13 – Investigating Hydraulic Fracturing in Tight Gas Sand and Shale Gas Reservoirs in the Cooper Basin 141
13.1 Abstract 141
13.2 Introduction 141
13.3 Cooper Basin Review 144
13.4 Prefracture Stimulation Planning 148
13.5 Fracture Stimulation Results 152
13.6 Discussion 159
13.7 Conclusions 161
13.8 Recommendations 161
13.9 Nomenclature 161
13.10 Acknowledgments 161
13.11 References 161
Chapter 14 – Integrated Field Study for Production Optimization: Jonah Field—Sublette County, Wyoming 165
14.1 Abstract 165
14.2 Introduction 165
14.3 Analysis Methodology 167
14.4 Integrated Study Analysis 168
14.5 Summary 175
14.6 Conclusions 175
14.7 Nomenclature 175
14.8 Acknowledgments 176
14.9 References 176
Chapter 15 – Producing Characteristics and Drainage Volume of Dakota Reservoirs, San Juan Basin, New Mexico 177
15.1 Abstract 177
15.2 Introduction 177
15.3 Dakota Reservoirs: Geology and Study Area 178
15.4 Rate-Time Type-Curve Analysis 178
15.5 Producing Characteristics of Dakota Wells 179
15.6 Example: A Three-Well Group 179
15.7 Drainage Volume, Drainage Area, Initial Gas-In-Place, and Productivity Index of Dakota Wells 182
15.8 Conclusions 182
15.9 Nomenclature 184
15.10 Acknowledgments 184
15.11 References 184
Appendix 15.A 185
15.A.1 Type Curves 185
Appendix 15.B 186
15.B.1 Type-Curve Analysis 186
Chapter 16 – Production Analysis of Commingled Gas Reservoirs—Case Histories 187
16.1 Abstract 187
16.2 Introduction 187
16.3 The Commingled Gas Flow Model 188
16.4 Case Histories 189
16.5 Discussion 198
16.6 Conclusions 198
16.7 Nomenclature 199
16.8 Acknowledgment 200
16.9 References 200
Chapter 17 – A Case History for Massive Hydraulic Fracturing the Cotton Valley Lime Matrix, Fallon and Personville Fields 201
17.1 Summary 201
17.2 Introduction 201
17.3 Reservoir Characteristics 202
17.4 Stimulation History 204
17.5 Reservoir Treatment 204
17.6 Optimization of Fracture Length and Well Spacing 209
17.7 Conclusions 211
17.8 Nomenclature 211
17.9 References 212
Appendix 17.A 212
Mechanics of a Super MHF Job 212
Appendix 17.B 214
Fracture Design 214
Appendix C.17.1 Logistics 214
Appendix D.17.1 Execution 215
Appendix 17.E Summary 218
Chapter 18 – Stimulation Optimization in a Low-Permeability Upper Devonian Sandstone Reservoir: A Case History 219
18.1 Summary 219
18.2 Introduction 219
18.3 Historical Reservoir and Stimulation Treatment Evaluation 220
18.4 Results of Preliminary Stimulation Design Changes 222
18.5 Final Stimulation Optimization Study 224
18.6 Application of Results 226
18.7 Conclusions 227
18.8 Nomenclature 227
18.9 References 227
Appendix 18A 228
18.A.1 Fracture Treatment Optimization 228
18.A.2 Authors 228
Chapter 19 – A Case Study of the Wilcox (Lobo) Trend in Webb and Zapata Counties, TX 229
19.1 Summary 229
19.2 Introduction 229
19.3 Geology 230
19.4 Completion and Testing Practices 231
19.5 Hydraulic Fracture Stimulation 232
19.6 Reservoir Study 233
19.7 Post-Fracture Evaluation 234
19.8 Conclusions 237
19.9 Acknowledgments 237
19.10 References 237
Chapter 20 – Fracture Stimulation of a Horizontal Well in a Deep, Tight Gas Reservoir: A Case History From Offshore The Netherlands 239
20.1 Abstract 239
20.2 Introduction 240
20.3 Completion Design 241
20.4 Fluid System 242
20.5 Fracture Design 243
20.6 Execution 244
20.7 Production Performance 247
20.8 Discussion 247
20.9 Conclusions 248
20.10 Acknowledgments 248
20.11 References 248
Chapter 21 – Integrated Reservoir Geomechanics Techniques in the Burgos Basin México: An Improved Gas Reservoirs Management 249
21.1 Abstract 249
21.2 Introduction 249
21.3 Stress and Physical Property Analysis in the Arcabuz Culebra Field, México 250
21.4 Fracture Mapping and Fracture Engineering 252
21.5 Integrated Reservoir Modelling 254
21.6 Conclusions 256
21.7 Acknowledgments 256
21.8 References 256
Chapter 22 – Case Histories—Combining Crossed Dipole Sonic Anisotropy and Oriented Perforating To Optimize Hydraulic Fracturing in the Burgos Basin—Reynosa, Mexico 259
22.1 Proposal 259
22.2 Stress Orientation and Borehole Breakout 260
22.3 Stress Orientation and Crossed Dipole Anisotropy Analysis 260
22.4 Dynamic and Static Elastic Moduli 260
22.5 Perforating for Low Permeability Hydraulic Stimulation 263
22.6 Observations and Recommendations. 268
22.7 References 269
Appendix 22.A 270
22.A.1 Authors 270
Chapter 23 – Economic Assessment of Applying Advances in Fracturing Technology 271
23.1 Summary 271
23.2 Introduction 271
23.3 Need for New Fracture Technology 272
23.4 Quantifying Technology-Application Benefits 274
23.5 Summary of Benefits 278
23.6 Conclusions 279
23.7 Nomenclature 279
23.8 References 279
Appendix 23.A 280
23.A.1 About the Authors 280
Bibliography 281