Contents
Chapter 1 Regional Geological Setting 1
1.1 Geological setting of the Junggar Basin 1
1.1.1 Overview of the basin 1
1.1.2 Structural evolution and structural unit division 2
1.2 Geological setting of the northwestern margin of the Junggar Basin 4
1.2.1 Geological setting 4
1.2.2 Structural evolution 6
Chapter 2 Reservoir Petrological Characteristics and Reservoir Space Types 10
2.1 Reservoir petrology 10
2.1.1 Volcanic breccia 10
2.1.2 Andesite 13
2.1.3 Basalt 15
2.1.4 Tuff 16
2.1.5 Clastic rock 17
2.2 Reservoir space types 19
2.2.1 Primary reservoir space 20
2.2.2 Secondary reservoir space 23
2.3 Factors influencing reservoir space development 27
2.3.1 Effect of lithology and lithofacies 27
2.3.2 Effect of dissolution 31
2.3.3 Effect of tectonic activity 32
Chapter 3 Oil-source Correlation and Migration Pathway Tracing 34
3.1 Geochemistry of source rocks 35
3.1.1 Evaluation criterion of source rocks 35
3.1.2 Evaluation of source rocks 36
3.1.3 Biomarkers of source rocks 42
3.2 Geochemical features of crude oil and oil-source correlation 45
3.2.1 Physical properties of crude oil 45
3.2.2 Geochemical features of crude oil and oil-source analysis 45
3.3 Migration pathways and tracing of crude oil 51
3.3.1 Conducting system of crude oil 51
3.3.2 Tracing of crude oil migration pathways 55
Chapter 4 Development Features of Reservoir Fractures 59
4.1 Development features of core fractures 59
4.1.1 Identification and statistic of fractures in coring sections 60
4.1.2 Filling features of fractures in coring sections 61
4.2 Imaging log responses of fractures 62
4.2.1 Imaging logging response of typical drilling fractures 65
4.2.2 High-conductivity fractures and high-resistivity fractures 77
Chapter 5 Geochemistry of Fracture Fillings 87
5.1 Isotope geochemistry 87
5.1.1 Sr isotope 87
5.1.2 C and O isotopes 93
5.2 Fluid inclusion geochemistry 99
5.2.1 Inclusion petrography 100
5.2.2 Fluorescence characteristics 103
5.2.3 Homogenization temperature 105
Chapter 6 Mechanical Properties of Reservoir Rocks 107
6.1 Rock mechanics characteristics 108
6.1.1 Sample information and test 108
6.1.2 Sample test procedure and results 110
6.1.3 Rock deformation characteristics 112
6.1.4 Rock mechanics parameters 117
6.2 Factors affecting mechanical properties of rock 119
6.2.1 Influence of rock types on mechanical properties 120
6.2.2 Influence of pre-existing weak planes on mechanical properties of rock 121
6.2.3 Influence of confining pressure on mechanical properties of rock 122
Chapter 7 Factors Affecting Fracture Development and Effectiveness 124
7.1 Factors affecting fracture development 124
7.1.1 Influence of lithology 124
7.1.2 Influence of formation thickness 126
7.1.3 Influence of structural position 126
7.2 Development stages of fractures 128
7.2.1 Sequence of fracture development 128
7.2.2 Tectonic evolution and fracture development stage 141
7.3 Fracture effectiveness and distribution 144
7.3.1 Analysis on fracture effectiveness 144
7.3.2 Distribution of effective fractures 147
References 151