Petroleum Geoscience

Preface to Second Edition xv Preface to First Edition xvii Acknowledgments xix 1 Introduction 1 1.1 The Aim and Format of the Book 1 1.2 Background 1 1.3 What Is in this Book 2 1.4 What Is Not in this Book 2 1.5 Key Terms and Concepts 3 1.5.1 Petroleum 3 1.5.2 The Source 3 1.5.3 The Seal 4 1.5.4 The Trap 4 1.5.5 The Reservoir 4 1.5.6 The Timing of Petroleum Migration 4 1.5.7 Porous Rock and Porosity 5 1.5.8 Permeable Rock and Permeability 5 1.5.9 Relative Permeability 5 1.5.10 Net to Gross and Net Pay 5 1.5.11 Water Saturation 5 1.5.12 Formation Volume Factor 5 1.5.13 The Gas to Oil Ratio 6 1.5.14 Timescales 6 1.5.15 The Units Used in this Book 6 1.6 The Chemistry of Petroleum 6 1.6.1 Alkanes (Paraffins) 9 1.6.2 Naphthenes (Cycloalkenes) 10 1.6.3 Aromatics 11 1.6.4 Asphaltenes 11 1.7 Geoscience and the Value Chain 12 1.7.1 Exploration (Chapters 3 and 4) 12 1.7.2 Appraisal (see Chapter 5) 13 1.7.3 Development (see Chapter 6) 13 1.7.4 Production (see Chapter 6) 14 1.7.5 Reserves Additions and Reserves Growth (see Chapter 6) 14 1.7.6 Field Abandonment and Reactivation (see Chapter 6) 14 1.7.7 Gas Storage (see Chapter 7) 15 1.7.8 Unconventional Petroleum (see Chapter 7) 15 1.8 Geoscience Activity 15 1.9 Oil, Gas, and Geoscientists – A Global Resource! 16 Further Reading 19 2 Tools 21 2.1 Introduction 21 2.2 Satellite Images and Other Remote Sensing Data 21 2.2.1 Introduction 21 2.2.2 Satellite Images 21 2.2.3 Gravimetric Data 22 2.2.4 Magnetic Data 24 2.2.5 Electromagnetic Surveys 25 2.3 Seismic Data 25 2.3.1 Introduction 25 2.3.2 The Seismic Method 27 2.3.3 Seismic Acquisition 29 2.3.3.1 Land 29 2.3.3.2 Water 29 2.3.3.3 Collection of Seismic Data: Receivers 30 2.3.4 Seismic Processing 30 2.3.5 Seismic Interpretation 30 2.4 Wireline Log Data 32 2.4.1 Introduction 32 2.4.2 Rock Tools 32 2.4.3 Seismic Enhancement 35 2.4.4 Porosity and Permeability Tools 37 2.4.5 Fluid Tools 40 2.4.6 Pressure Tool 42 2.5 Core and Cuttings 43 2.5.1 Introduction 43 2.5.2 Conventional Core Analysis (Porosity and Permeability) 45 2.5.2.1 Sample Acquisition 45 2.5.2.2 Sample Cleaning 45 2.5.2.3 Sample Drying 45 2.5.2.4 Porosity Measurements 47 2.5.2.5 Permeability Measurements 47 2.5.3 Core Logging 49 2.5.4 Petrography 49 2.5.4.1 Provenance 49 2.5.4.2 The Depositional Environment 51 2.5.4.3 Reservoir Quality 51 2.5.5 Geochemistry 52 2.5.6 Biostratigraphy 52 2.5.6.1 Sampling 53 2.5.6.2 Correlation 53 2.5.6.3 Age Dating 53 2.5.6.4 The Depositional Environment 53 2.6 Fluid Samples From Wells 54 2.6.1 Introduction 54 2.6.2 The Sampling of Fluids 54 2.6.3 Petroleum 55 2.6.3.1 Gas Chromatography and Gas Chromatography (GC) Fingerprinting 55 2.6.3.2 Molecular Maturity 56 2.6.3.3 Rhenium–Osmium Dating 56 2.6.4 Water 56 2.7 Outcrop Data 57 2.7.1 Introduction 57 2.7.2 Maps 57 2.7.3 Reservoir Analogs 59 2.7.4 Rock Sampling and Analysis 59 2.8 Seepage of Petroleum 60 Further Reading 61 3 Frontier Exploration 63 3.1 Introduction 63 3.2 Acquisition of Acreage 66 3.2.1 Early Access to Acreage 66 3.2.2 The Licensing Process 67 3.2.3 License Areas 68 3.2.4 Farm-Ins, Farm-Outs, and Other Deals 69 3.3 Direct Petroleum Indicators 69 3.3.1 Introduction 69 3.3.2 Petroleum Leakage and Seepage 69 3.3.2.1 Seal Failure 70 3.3.2.2 Tertiary Migration 71 3.3.2.3 Dissipation in the Near Surface 72 3.3.3 The Identification of Petroleum on Seismic Data 72 3.4 Basin Types 76 3.4.1 Introduction 76 3.4.2 Extensional Basins, Generated by Divergent Plate Motion 78 3.4.2.1 Intracratonic Basins: Sags 78 3.4.2.2 Rift Basins 78 3.4.2.3 Passive Margins 79 3.4.3 Basins Generated During Convergent Plate Motion 82 3.4.3.1 Arc Systems 83 3.4.3.2 Foreland Basins 83 3.4.4 Strike-Slip Basins 84 3.5 Basin Histories 84 3.5.1 Introduction 84 3.5.2 Subsidence 85 3.5.3 Sediment Supply 88 3.5.4 Burial History 89 3.5.5 Thermal History 91 3.5.6 Uplift 92 3.5.7 Pressure History 93 3.5.8 Integrated Basin Modeling 95 3.6 Stratigraphy 96 3.6.1 Introduction 96 3.6.2 Chronostratigraphy 97 3.6.3 Biostratigraphy 97 3.6.4 Lithostratigraphy 100 3.6.5 Seismic Stratigraphy 102 3.6.5.1 Rift Basins 104 3.6.5.2 Passive Margins 104 3.6.5.3 Foreland Basins 105 3.6.5.4 Wrench Systems 105 3.6.6 Sequence Stratigraphy 106 3.6.7 Chemostratigraphy and Magnetostratigraphy 111 3.6.8 Stratigraphic Tests 111 3.7 Source Rock 112 3.7.1 Introduction 112 3.7.2 The Origin of Petroleum from Living Organisms 112 3.7.2.1 Organic Matter 112 3.7.2.2 Preservation of Organic Matter 112 3.7.3 Kerogen 114 3.7.3.1 Kerogen Type 114 3.7.3.2 The Quantity and Quality of Kerogen 115 3.7.4 Maturation of Source Rocks: Kerogen to Oil to Gas 116 3.7.4.1 Temperature 116 3.7.4.2 The Kinetics of Hydrocarbon Generation 116 3.7.4.3 Reaction Products 117 3.7.4.4 Maturation in the Reservoir 117 3.7.4.5 Bitumen and Tar Mats 117 3.8 Jubilee Field, Ghana, West Africa 119 3.8.1 Introduction 119 3.8.2 Basin Setting 120 3.8.3 Pre-Drill Assessment 120 3.8.4 Jubilee Field 121 3.8.5 Implications for West African and South American Margins 122 3.9 Johan Sverdrup Oilfield, Norwegian North Sea 122 3.9.1 Introduction 122 3.9.2 Location 122 3.9.3 Early Exploration History 123 3.9.4 Renewed Interest 123 3.9.5 Major Discovery 125 3.9.6 Petroleum Geology 125 3.9.7 Learning 126 Further Reading 127 4 Exploration and Exploitation 129 4.1 Introduction 129 4.2 The Seal 129 4.2.1 Introduction 129 4.2.2 The Membrane Seal 130 4.2.3 The Hydraulic Seal 131 4.2.4 Faults 132 4.2.5 Trap Fill 133 4.2.6 The Pressure Seal 134 4.3 The Reservoir 135 4.3.1 Introduction 135 4.3.2 Intrinsic Properties 136 4.3.2.1 Net to Gross 136 4.3.2.2 Porosity 137 4.3.2.3 Permeability 139 4.3.2.4 Water, Oil, and Gas Saturation 139 4.3.3 Reservoir Lithologies 140 4.3.4 The Reservoir: Sandstone Depositional Systems 143 4.3.4.1 Alluvial Fans 143 4.3.4.2 Aeolian Dunes 144 4.3.4.3 Lakes 145 4.3.4.4 Fluvial Systems 145 4.3.4.5 Deltas 148 4.3.4.6 Shallow-Marine Systems 148 4.3.4.7 Submarine Fans 150 4.3.5 The Reservoir: Limestone and Dolomite 151 4.3.5.1 Shelfal and Ramp Carbonates 152 4.3.5.2 Reefs 152 4.3.5.3 Deep-Water Carbonates 154 4.3.5.4 Dolomite 154 4.3.5.5 Karst 155 4.3.6 Fractured Reservoirs 156 4.4 Migration 157 4.4.1 Introduction 157 4.4.2 Primary Migration 158 4.4.3 Secondary Migration 161 4.4.4 Tertiary Migration 167 4.5 The Trap 168 4.5.1 Introduction 168 4.5.2 Migration and Trap Formation 173 4.5.3 Structural Traps 173 4.5.3.1 Traps Formed by Compressive Tectonic Processes 173 4.5.3.2 Traps Formed by Extensional Tectonic Processes 175 4.5.3.3 Traps Formed by Diapiric Processes 176 4.5.3.4 Traps Formed by Compactional Processes 182 4.5.3.5 Traps Formed by Gravity Processes 183 4.5.4 Stratigraphic Traps 185 4.5.4.1 Traps Formed by Depositional Pinchout 185 4.5.4.2 Traps Formed by Unconformities 186 4.5.4.3 Traps Formed by Diagenetic Processes 190 4.5.5 Hydrodynamic Traps 191 4.6 Play and Play Fairway 193 4.6.1 Play 193 4.6.2 Play Fairway 193 4.7 Lead and Prospect 195 4.7.1 Introduction 195 4.7.2 Lead, Prospect, and Prospect Evaluation 195 4.7.3 The Prospect Inventory 198 4.7.4 Well Prognosis 198 4.7.5 Failure Analysis 199 4.8 Yet to Find 199 4.8.1 Introduction 199 4.8.2 Areal Richness and Prospect Summation 200 4.8.3 Pool Size Distribution 201 4.8.4 Creaming Curves and Destruction of Value 203 4.9 Risk and Uncertainty 204 4.9.1 Introduction 204 4.9.2 Risk 205 4.9.3 Uncertainty 207 4.10 Thunder Horse Field, Gulf of Mexico, USA 208 4.10.1 Introduction 208 4.10.2 Geology 209 4.10.3 Deep Water Subsalt Exploration 211 4.10.4 Discovery, Appraisal, and Field Start-Up 212 4.11 Clyde Field, UK North Sea 213 4.11.1 Introduction 213 4.11.2 Great Expectations 214 4.11.3 Reality Dawns 214 4.11.4 A Change of Owner 215 Further Reading 217 5 Appraisal 219 5.1 Introduction 219 5.2 The Trap Envelope 221 5.2.1 Depth Conversion 221 5.2.2 Mapping Surfaces and Faults 223 5.2.3 Spill Points 228 5.3 Fluid Distribution and Contacts 230 5.3.1 Fluid Contacts and Transition Zones 230 5.3.2 Intra-Field Variations in Petroleum Composition 233 5.3.3 Intra-Field Variations in Water Composition 237 5.4 Field Segmentation 238 5.4.1 Introduction 238 5.4.2 Barriers to Lateral Flow 238 5.4.3 Barriers to Vertical Flow 241 5.4.4 Identification of Flow Barriers 241 5.5 Reservoir Property Distribution 243 5.5.1 Introduction 243 5.5.2 Lithofacies and Lithotypes 243 5.5.3 Reservoir Body Geometry 245 5.5.4 Reservoir Correlation 247 5.6 Reservoir Quality 249 5.6.1 Introduction 249 5.6.2 More Intrinsic Reservoir Properties 249 5.6.2.1 Relative Permeability 250 5.6.2.2 Wettability 252 5.6.2.3 Resistivity, Cementation, and Tortuosity Factors 252 5.6.3 Controls on Reservoir Quality 252 5.6.4 Compaction and Cementation in Sandstones 253 5.6.4.1 Sand Compaction 253 5.6.4.2 Sand Cementation 254 5.6.5 Compaction and Cementation in Limestones 257 5.6.5.1 Near-Surface Processes 257 5.6.5.2 Compaction and Burial Processes 262 5.7 Reservoir Description from Seismic Data 263 5.7.1 Introduction 263 5.7.2 Lithology Description 264 5.7.3 Porosity Determination 265 5.7.4 Lateral Variations and Reservoir Heterogeneity 265 5.7.5 Reservoir Correlation 267 5.7.6 Identification of Fluid Type and Contacts 268 5.8 Petroleum in Place, Reservoir Models, and Reserves 268 5.8.1 Introduction 268 5.8.2 Petroleum in Place 268 5.8.3 Geologic Models 269 5.8.4 Reservoir Models 274 5.8.5 Reserves 275 5.9 Kadanwari Field, Pakistan 277 5.9.1 Introduction 277 5.9.2 Re-Evaluation of Seismic Data over Kadanwari 280 5.10 Pedernales Field, Venezuela 281 5.10.1 Introduction 281 5.10.2 Geology of the Area 281 5.10.3 History of Exploration and Production 283 5.10.4 Field Reactivation, 1990s 285 Further Reading 287 6 Development and Production 289 6.1 Introduction 289 6.2 Well Planning and Execution 290 6.2.1 Facilities Location and Well Numbers 290 6.2.2 Well Geometries 294 6.2.3 Well Types 298 6.2.4 Drilling Hazards 298 6.2.5 Well Completion and Stimulation 300 6.2.6 Formation Damage 300 6.2.7 Well Logging and Testing 303 6.3 Reservoir Management 307 6.3.1 Reservoir Description from Production Data 307 6.3.2 Reservoir Visualization 309 6.3.3 Time-Lapse Seismic 312 6.3.4 Managing Decline and Abandonment 315 6.4 Reserves Revisions, Additions, and Field Reactivation 316 6.4.1 Introduction 316 6.4.2 Reserves Revisions 316 6.4.3 Reserves Additions 317 6.4.4 Field Rehabilitation and Reactivation 318 Case Histories 319 6.5 Thistle Field, North Sea – Improving Late Field Life Oil Production 319 6.5.1 Introduction 319 6.5.2 Field Production Profiles 320 6.5.3 Water Cut and Ultimate Oil Recovery 321 6.5.4 Voidage Replacement, Pressure Maintenance, and Sweep 323 6.5.5 Conclusions 325 6.6 Ardmore Field, UKCS 326 6.6.1 Introduction 326 6.6.2 Location and History 326 6.6.3 Structure and Stratigraphy 327 6.6.3.1 Devonian 327 6.6.3.2 Permian – Rotliegend and Zechstein 327 6.6.3.3 Upper Jurassic Humber Group 329 6.6.3.4 Upper Cretaceous – Paleocene Chalk Group 329 6.6.3.5 Paleocene/Eocene – Recent Stronsay, Westray, and Nordland Groups 330 6.6.4 Reservoirs 330 6.6.4.1 Upper Devonian 330 6.6.4.2 Rotliegend 330 6.6.4.3 Zechstein 331 6.6.4.4 Upper Jurassic 331 6.6.5 Source 331 6.6.6 STOIIP and Reserves 331 6.6.7 Argyll Production 332 6.6.8 Ardmore Development and Production 332 6.6.9 Conclusions 335 6.6.10 Postscript 335 Further Reading 335 7 Unconventional Petroleum, Gas Storage, Carbon Storage, and Secondary Products 337 7.1 Introduction 337 7.1.1 Unconventional Gas 337 7.1.2 Unconventional Oil 339 7.1.3 Gas Storage 340 7.2 Unconventional Gas 340 7.2.1 Tight Gas Reservoirs 340 7.2.2 Shale Gas 342 7.2.3 Low Saturation Gas 346 7.2.4 Shallow Gas 347 7.2.5 Basin-Center Gas 348 7.2.6 Gas Hydrates 349 7.2.7 Coal Bed Methane 350 7.2.8 Coal Mine Methane 351 7.3 Unconventional Oil 351 7.3.1 Heavy Oil and Tar Sand 351 7.3.2 Shale Oil and Oil Shale 352 7.4 Underground Coal Gasification 354 7.5 Gas Storage 356 7.6 Carbon Storage 357 7.7 Heat, Helium, and Other Secondary Products 360 7.7.1 Heat Recovery 360 7.7.2 Lithium and Other Solutes 362 7.7.3 Helium 363 7.8 Dunlin Field, UK North Sea, Opportunities for Power Generation from Unconventional Gas and/or Co-Produced Water 364 7.8.1 Introduction 364 7.8.2 Deep (Shale) Gas 366 7.8.3 Shallow Gas 366 7.8.4 Co-Produced Hot Water 367 7.9 Clipper South Field, UK North Sea – Development of a Tight Gas Field 371 7.9.1 Introduction 371 7.9.2 Re-Evaluation of the Field 371 7.9.3 Analysis of Well Test Data 372 References 375 Index 401