Page 11 - Geology of Carbonate Reservoirs

viii CONTENTS

6.2 Diagenetic Porosity / 150
6.3 Diagenetic Environments and Facies / 153
6.3.1 Diagenetic Facies / 155
6.4 Diagenetically Enhanced Porosity / 156
6.4.1 Enhancement by Recrystallization / 158
6.4.2 Enhancement by Solution Enlargement / 160
6.4.3 Large-Scale Dissolution-Related Porosity / 161
6.4.4 Porosity Enhancement by Replacement / 163
6.4.5 Recognizing Enhanced Porosity / 163
6.5 Porosity Reduction by Diagenesis / 164
6.5.1 Pore Reduction by Compaction / 165
6.5.2 Pore Reduction by Recrystallization / 165
6.5.3 Pore Reduction by Replacement / 166
6.5.4 Pore Reduction by Cementation / 167
6.5.5 Recognizing Diagenetically Reduced Porosity / 170
6.6 Diagnosing and Mapping Diagenetic Reservoirs / 171
Suggestions for Further Reading / 174
Review Questions / 175

7 FRACTURED RESERVOIRS 176

7.1 Fractures and Fractured Reservoirs / 176

7.1.1 Definition of Fractures / 177
7.1.2 Types of Fractures / 177
7.1.3 Genetic Classification of Fractures / 178

7.1.4 Fracture Morphology / 181
7.1.5 Where Do Fractures Occur? / 184
7.2 Fracture Permeability, Porosity, and S w / 186
7.2.1 Fracture Permeability / 187
7.2.2 Fracture Porosity / 188
7.2.3 S w in Fractured Reservoirs / 189
7.3 Classification of Fractured Reservoirs / 190

7.4 Detecting Fractured Reservoirs / 191
7.4.1 Direct Observation of Fractures in the Borehole / 192
7.4.2 Indirect Methods to Detect Fractures in the
Borehole / 192
7.5 Predicting Reservoir Fracture Spacing and Intensity / 195

7.5.1 Factors that Influence Fracture Spacing and
Intensity / 195
7.6 Identifying and Developing Fractured Reservoirs / 195
Suggestions for Further Reading / 198
Review Questions / 198