Table of Contents
Preface xi
1 Introduction to rock physics 1
1.1 Introduction 1
1.2 Velocity-porosity relations for mapping porosity and facies 2
1.3 Fluid substitution analysis 15
1.4 Pressure effects on velocity 24
1.5 The special role of share wave information 30
1.6 Rock physics "What ifs?": fluid and lithology substitution 42
1.7 All models are wrong…some are useful 43
2 Rock physics interpretation of texture, llithology and compaction 48
2.1 Introduction 48
2.2 The link between rock physics properties and sedimentary microstructure: theory and models 51
2.3 Example: rock physics interpretation of microstructure in North Sea turbidite systems 70
2.4 Relating rock physics to lithofacies and depositional environments 81
2.5 Example: seismic lithofacies in a North Sea turbidite system 83
2.6 Rock physics depth trends 90
2.7 Example: rock physics depth trends and anomalies in a North Sea field 96
2.8 Rock physics templates: a tool for lilthology and fluid prediction 101
2.9 Discussion 107
2.10 Conclusions 109
3 Statistical rock physics: Combining rock physics, information theory, and statistics to reduce uncertainty 111
3.1 Introduction 111
3.2 Why quantify uncertainty? 112
3.3 Statistical rock physics workflow 123
3.4 Information entropy: some simple examples 132
3.5 More Carlo simulation 136
3.6 Statistical classification and pattern recongniition 138
3.7 Discussion and summary 165
4 Common techniques for Quantitative seismic interpretation 168
4.1 Introduction 168
4.2 Qualitative seismic amplitude interpretation 168
4.3 AVO analysis 180
4.4 Impedance inveersion 230
4.5 Forward seismic modeling 252
4.6 Future directions in quantitative seismic interpreetation 256
5 Case studies: Lithology and pore-fluid prediction from seismic data 258
5.1 Case 1: Seismic reservoir mapping from 3D AVO in a North Sea turbidite system 258
5.2 Case 2: Mapping lithofacies and pore-fluid probabilities in a North Sea reservoir using seismic impedance inversions and statistical rock physics 278
5.3 Case 3: Sesimic lithology prediction and reservoir delineation using statistical AVO in the Grane field, North Sea 295
5.4 Case 4: AVO depth trends for lithology and pore fluid classification in unconsolidated deep-water systems, offshore West Africa 306
5.5 Case 5: Sesimic reservoir mapping using rock physics templates. Example from a North Sea turbidite system 312
6 Workflows and Guidelines 317
6.1 AVO reconnaissance 318
6.2 Rock physics "What ifs" and AVO feasibility studies 320
6.3 RPT analysis 322
6.4 AVO classification constrained by rock physics depth trends 323
6.5 Seismic reservoir characterization constrained by lithofacies analysis and statistical rock physics 325
6.6 Why and when should we do quantitative seismic interpretation? 328
7 Hands-on 332
7.1 Introduction 332
7.2 Problems 332
7.3 Project 336
References 340
Index 356
