Fundamentals of Petroleum Reservoir Engineering (Fluid & Rock Properties)

Chapter One: Basic Concepts and Equations
1.1 What is Reservoir Engineering……………………………………………. 1
1.2 Some information about hydrocarbons……………………………………. 1
1.3 Temperature Scales………………………………………………………... 2
1.4 Equation of State…………………………………………………………... 3
1.4.1 Ideal Gas Law………………………………………………………… 3
1.4.1.1 Boyle’s Law…………………………………………………......... 4
1.4.1.2 Charles’s Law…………………………………………………….. 5
1.4.1.3 Gay-Lussac’s Law………………………………………………... 6
1.4.1.4 The Combined Gas Law………………………………………….. 6
1.4.1.5 Avogadro’s Law………………………………………………….. 7
1.4.1.6 Molecular Weight (Molar Mass) …………………………...……. 8
1.4.1.7 The Universal Gas Constant (R) ……………………………......... 8
1.4.1.8 Dalton’s Law …………………………………………………….. 10
1.4.1.9 Amagat’s Law ……………………………………………………. 11
1.4.2 Real Gas Law ………………………………………………………… 11
1.4.2.1 Van der Waals Equation ………………………………………… 13
Problems …………………………………………………………………..……..
References …………………………………………………………………...…...
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Chapter Two: Natural Gas & Crude Oil Properties
2.1 Natural Gas Properties ……………………………………………………. 18
2.1.1 Apparent Molecular Weight (Ma) and Mole Fraction (yi)…………… 18
2.1.2 Gas Density, ρg ……………………………………………………….. 20
2.1.3 Specific Gravity, γg …………………………………………………… 21
2.1.4 Specific volume, ν…………………………………………………….. 23
2.1.5 Critical Temperature and Pressure……………………………………. 23
2.1.5.1 Single-Component Systems………………………………………. 23
2.1.5.2 Two-Component Systems………………………………………… 28
2.1.5.3 Three-Component Systems……………………………………….. 30
2.1.5.4 Multicomponent Systems………………………………………… 31
2.1.5.5 Principle of Corresponding States………………………………... 32
2.1.6 Determination of Z-factor Value……………………………………… 32
2.1.7 Isothermal Gas Compressibility, cg…………………………………... 50
2.1.8 Gas Formation Volume Factor, Bg……………………………………. 54
2.1.9 Gas Expansion Factor, Eg……………………………………………... 55
2.1.10 Gas Viscosity, μg……………………………………………………… 56
2.2 Crude Oil Properties ……………………………………………………… 62
2.2.1 Crude Oil API Gravity………………………………………………... 62
2.2.2 Specific Gravity of the Solution Gas, "??"…………………………… 64
2.2.3 Crude Oil Density, "??"………………………………………………. 65
2.2.4 Gas Solubility “??”…………………………………………………… 66
2.2.5 Bubble Point Pressure “??”…………………………………………… 68
2.2.6 Oil Formation Volume Factor “??”…………………………………... 69
2.2.7 Isothermal Compressibility Coefficient of Crude Oil "??"…………… 71
2.2.8 Total Formation Volume Factor “?t”………………………………… 73
2.2.9 Crude Oil Viscosity “??”……………………………………………... 75
Problems…………………………………………………………………………..
References………………………………………………………………………...
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Chapter Three: Phase Behavior and Laboratory Analysis of
Reservoir Fluids
3.1 Phase Behavior……………………………………………………………. 87
3.2 Classification of Reservoirs……………………………………………….. 89
3.2.1 Classification of Oil Reservoirs………………………………………. 92
3.2.2 Classification of Gas Reservoirs……………………………………… 92
3.3 Classification of Crude Oils………………………………………………. 96
3.4 Laboratory Analysis of Reservoir Fluids…………………………………. 99
3.4.1 Well Conditioning…………………………………………………….. 99
3.4.2 Fluid Sampling………………………………………………………... 99
3.4.3 PVT Laboratory Tests………………………………………………… 101
3.4.4 Compositional Analysis of the Reservoir Fluid (chromatographic
Test)…………………………………………………………………… 102
3.4.5 Constant-Composition Expansion Tests (Equilibrium Test)…………. 103
3.4.6 Differential Liberation Test (DL)……………………………………... 109
3.4.7 Separator Tests………………………………………………………... 119
3.4.7.1 Differential and Flash Separation………………………………… 121
3.4.7.2 Single-Stage Separation…………………………………………... 122
3.4.7.3 Two-Stage Separation…………………………………………….. 123
3.4.7.4 Relationship of Gasoline Plants in Separation…………………… 124
3.4.7.5 Economic Summary……………………………………………… 125
Problems…………………………………………………………………………..
References………………………………………………………………………...
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Chapter Four: Basic Reservoir Rock Properties
4.1 Porosity……………………………………………………………………. 130
4.1.1 Factors Affecting Sandstone Porosity………………………………… 132
4.1.2 Factors Affecting Carbonate Porosity………………………………… 133
4.1.3 Typical Reservoir Porosity Values……………………………………. 134
4.1.4 Porosity Averaging……………………………………………………. 134
4.1.5 Laboratory Measurement of Porosity…………………………………. 135
4.1.5.1 Bulk Volume Measurement………………………………………. 136
4.1.5.2 Pore Volume Measurement………………………………………. 137
4.1.5.3 Grain Volume Measurement……………………………………... 140
4.1.5.4 Indirect Methods of Porosity Measurement (Logging Method)….. 140
4.1.6 Pore Volume Compressibility………………………………………… 141
4.2 Fluid Saturation…………………………………………………………… 142
4.2.1 Saturation Averaging…………………………………………………. 144
4.2.2 Laboratory Measurement of Fluid Saturation………………………… 145
4.3 Permeability……………………………………………………………….. 147
4.3.1 Averaging Absolute Permeabilities…………………………………… 153
4.3.1.1 Parallel Flow……………………………………………………… 153
4.3.1.2 Series Flow……………………………………………………….. 157
4.3.1.3 Geometric Average Permeability………………………………… 161
4.3.2 Absolute Permeability Correlations…………………………………... 162
4.3.3 Permeability of Fractures and Channels……………………………… 163
4.3.4 Factors Affecting Absolute Permeability……………………………... 164
4.3.5 Laboratory Measurement of Absolute Permeability………………….. 164
4.3.6 Klinkenberg Effect..…………………………………………………... 166
4.4 Surface and Interfacial Tensions………………………………………….. 168
4.4.1 Effect of Pressure and Temperature on Interfacial and Surface
Tension………………………………………………………………... 171
4.4.2 Laboratory Measurement of Interfacial Tension……………………… 172
4.5 Wettability………………………………………………………………… 172
4.5.1 Classification or Types of Wettability………………………………... 174
4.5.1.1 Water Wet………………………………………………………… 174
4.5.1.2 Oil Wet…………………………………………………………… 175
4.5.1.3 Intermediate Wet…………………………………………………. 175
4.5.1.4 Fractional Wettability…………………………………………….. 175
4.5.1.5 Mixed Wettability………………………………………………… 175
4.5.2 Factors Affecting Wettability…………………………………………. 176
4.5.3 Measurement of Reservoir Rock Wettability…………………………. 176
Problems…………………………………………………………………………..
References………………………………………………………………………...
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Chapter Five: Capillary Pressure and Relative Permeability
5.1 Capillary Pressure…………………………………………………………. 182
5.1.1 Dependence of Capillary Pressure on Rock and Fluid Properties……. 186
5.1.2 Laboratory Measurement of Capillary Pressure……………………… 187
5.1.3 Averaging Capillary Pressure Data: J-Function………………………. 190
5.1.4 Converting Laboratory Capillary Pressure Data to Reservoir
Conditions…………………………………………………………….. 193
5.1.5 Capillary Pressure and Permeability………………………………….. 194
5.1.6 Zonation, Fluid Contacts, and Initial Saturation Distribution in a
Reservoir……………………………………………………………… 195
5.1.6.1 Free Water Level, FWL…………………………………………... 197
5.1.6.2 Oil-Water Contact, OWC………………………………………… 198
5.1.6.3 Transition Zone…………………………………………………… 200
5.2 Relative Permeability……………………………………………………… 204
5.2.1 Two-Phase Relative Permeability…………………………………….. 205
5.2.1.1 Drainage Process…………………………………………………. 209
5.2.1.2 Imbibition Process………………………………………………... 210
5.2.2 Laboratory Measurement of Tow-Phase Relative Permeability……… 210
5.2.3 Two-Phase Relative Permeability Correlations………………………. 212
5.2.3.1 Wyllie and Gardner Correlation………………………………….. 212
5.2.3.2 Torcaso and Wyllie Correlation………………………………….. 215
5.2.4 Three-Phase Relative Permeability…………………………………… 215
Problems…………………………………………………………………………..
References………………………………………………………………………...
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Chapter Six: Introduction to Reserve Estimation
6.1 Introduction………………………………………………………………... 224
6.1.1 Reserve Status Categories…………………………………………….. 225
6.1.2 Reserve Estimation Methods………………………………………….. 225
6.2 Oil Recovery Methods…………………………………………………….. 226
6.3 Reservoir Primary Recovery Mechanisms………………………………... 228
6.3.1 Rock and Liquid Expansion…………………………………………... 228
6.3.2 The Depletion-Drive Mechanism……………………………………... 229
6.3.3 Gas-Cap Drive………………………………………………………… 229
6.3.4 The Water-Drive Mechanism…………………………………………. 230
6.3.5 The Gravity-Drainage-Drive Mechanism…………………………….. 231
6.3.6 The Combination-Drive Mechanism………………………………….. 232
6.4 Volumetric Methods………………………………………………………. 233
6.4.1 Oil Reservoirs…………………………………………………………. 233
6.4.2 Gas Reservoirs………………………………………………………... 235
6.5 Material Balance Equation………………………………………………... 236
6.6 Decline Curve Analysis and History Matching……………………………. 246
6.7 Reservoir Simulation……………………………………………………… 246
Problems…………………………………………………………………………..
References………………………………………………………………………...
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Index……………………………………………………………………………… 251