Page 9 - Fundamentals of Gas Shale Reservoirs

CONTENTS vii
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
4.6.1 Barnett Shale (Devonian), 74
4.6.2 Woodford Shale (Late Devonian–Early Mississippian), 74
4.6.3 Marcellus Shale (Devonian), 78
4.6.4 New Albany Shale (Upper Devonian–Lower Mississippian), 78
4.7 Mesozoic Resource Shale Examples, 80
4.7.1 Montney Formation (Early Triassic), 80
4.7.2 Haynesville/Bossier Shales (Late Jurassic), 80
4.7.3 Eagle Ford Formation (Cretaceous), 80
4.7.4 LaLuna Formation (Upper Cretaceous), 82
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
5.1.1 Gas Shales and Their Challenges, 89
5.1.2 Pore Size Classification, 90
5.2 Samples Characteristics, 90
5.2.1 Sample Collection, 90
5.2.2 Mineral Composition, 90
5.3 Experimental Methodology, 91
5.3.1 Capillary Pressure Profile, 91
5.3.2 Nitrogen Adsorption (N ), 92
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5.3.3 Low‐Field NMR, 92
5.3.4 Image Acquisition and Analysis, 93
5.4 Advantages and Disadvantages of Experimental PSD Methods, 95
5.5 Permeability Measurement, 95
5.6 Results, 96
5.6.1 Pore Size Distribution from MICP Experiments, 96
5.6.2 Pore Size Distribution from Nitrogen Adsorption Experiments, 98
5.6.3 NMR T Relaxation Time, 98
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5.6.4 Scanning Electron Microscopy, 100
5.6.5 Focused Ion Beam/Scanning Electron Microscopy, 100
5.6.6 Capillary Pressure and Permeability, 102
5.7 Discussion, 103
5.7.1 Porosity and PSD Comparisons, 103
5.7.2 Interchanging MICP with NMR Data, 103
5.7.3 Pore‐Body to Pore‐Throat Size Ratio: Pore Geometry Complexity, 107
5.7.4 Pore Throat Size and Permeability, 107
5.7.5 Mineralogy, 108
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
6.2.1 Pore System Characteristics, 117
6.2.2 Organic Matter Characteristics, 118
6.2.3 Permeability, 118