Preface ix Chapter 1 Introduction 1 1.1 Multiphase flow in the well 2 1.2 Methods 3 1.2.1 Theoretical analysis 3 1.2.2 Experimental study 3 1.2.3 Numerical simulation 4 1.3 Parameters 5 1.4 Multiphase Flow Patterns 9 1.4.1 Flow Patterns of Gas-Liquid Flow 9 1.4.2 Gas-Liquid Flow Pattern of Acid Gas Under Supercritical Condition 14 1.5 Multiphase Flow Models 19 1.5.1 Homogeneous Flow Model 19 1.5.2 Separated Flow Model 20 1.5.3 Drift-Flux Model 22 1.5.4 Statistical Average Model 24 Chapter 2 The Void Fraction Wave and Flow Regime Transition 25 2.1 Introduction 25 2.1.1 Bubble Coalescence and Flow Regime Transition 25 2.1.2 Void Fraction Wave and Flow Regime Transition 28 2.2 Experimental Setup and Methods 32 2.2.1 Experimental Setup 32 2.2.2 Observation and Determination of Flow Regimes 33 2.2.3 Flow Resistance Measurement 35 2.2.4 Flow Rate and Void Fraction Wave Measurement 35 2.2.5 Data Processing 37 2.3 Formation Mechanism of Slug Flow With Low Continuous Phase Velocity 38 2.3.1 Flow Regime Transition 38 2.3.2 Analytical Method 40 2.3.3 Experimental Results 46 2.3.4 Discussion on the Instability of Void Fraction Wave and Formation Mechanism of Taylor Bubble 49 2.3.5 Propagation Velocity of Void Fraction Wave 52 2.4 Gas-Liquid Flow Regime Transition with High Continuous Phase Velocity 54 2.4.1 Flow Regime Transition 54 2.4.2 Experimental Results and Discussions 55 2.4.3 Mechanism of Losing Stability for Bubbly Flow 62 2.4.4 Velocity of Void Fraction Wave 68 2.4.5 Non-Linear Properties of the Void Fraction Wave 71 Chapter 3 Multiphase Flow Model for Well Drilling 75 3.1 Continuity Equation 76 3.1.1 Continuity Equation in the Annulus 76 3.1.2 Continuity Equation in the Drilling Stem 81 3.2 Momentum Equation 82 3.2.1 Momentum Equation in the Annulus 82 3.2.2 Momentum Equation in the Drilling Stem 83 3.3 Energy Equation 85 3.3.1 Energy Equation in the Annulus 85 3.3.2 Energy Equation in the Drilling Stem 89 3.4 Applications of the Model 89 3.4.1 Underbalanced Drilling 89 3.4.2 Kicking and Killing 90 3.4.3 Kicking and Killing After Acid Gas Influx 92 3.4.4 Kicking and Killing for Deepwater Drilling 93 Chapter 4 Multiphase Flow During Underbalanced Drilling 97 4.1 Flow Model 98 4.1.1 Flow-Governing Equations in the Annulus 98 4.1.2 Flow-Governing Equations in the Drilling Stem 99 4.1.3 Energy Equations 100 4.1.4 Auxiliary Equations 101 4.2 Solving Processing 111 4.2.1 Definite Conditions 111 4.2.2 Discretization of the Model 112 4.2.3 Algorithms 115 4.3 Case Study 118 4.3.1 Gas Drilling 118 4.3.2 Drill Pipe Injection-Aerated Drilling 125 4.3.3 Annulus Injection-Aerated Drilling 128 Chapter 5 Multiphase Flow During Kicking and Killing 133 5.1 Common Killing Method 134 5.1.1 Killing Parameters of Driller’s Method and Wait and Weight Method 134 5.1.2 The Circulate-and-Weight Method 138 5.2 Multiphase Flow Model 139 5.2.1 Governing Equations for Killing 140 5.2.2 Governing Equation for Kicking 143 5.2.3 Auxiliary Equations 143 5.3 Solving Process 143 5.3.1 Definite Conditions 143 5.3.2 Discretization of the Model 146 5.3.3 Algorithms 148 5.4 Case Study 149 5.4.1 Basic Parameters of the Well 149 5.4.2 Simulations of Overflow 150 5.4.3 Hydraulic Parameters for Killing 151 Chapter 6 Multiphase Flow During Kicking and Killing with Acid Gas 155 6.1 Flow Model 156 6.1.1 Flow Governing Equations for Killing Acid Gas Kicking 156 6.1.2 Flow Governing Equations for Acid Gas Kicking 158 6.1.3 Auxiliary Equations 158 6.2 The Solving Process 160 6.2.1 Definite Conditions 160 6.2.2 Algorithms 163 6.3 Simulations and Case Study 164 6.3.1 Basic Parameters of the Well 164 6.3.2 Acid Gas Compressibility and Density in the Wellbore 164 6.3.3 Acid Gas Solubility in the Wellbore 166 6.3.4 Acid Gas Expansion in the Wellbore 168 6.3.5 Impact on the Pit Gain 169 Chapter 7 Multiphase Flow During Kicking and Killing in Deepwater Drilling 173 7.1 Common Deepwater Killing Method 174 7.1.1 Dynamic Killing Method 174 7.1.2 Advanced Driller’s Method 176 7.1.3 Additional Flow Rate Method 178 7.2 Flow Model 181 7.2.1 Governing Equations for Deepwater Well Killing 182 7.2.2 Governing Equations for Kicking 188 7.2.3 Auxiliary Equations 189 7.3 The Solving Process 191 7.3.1 Definite conditions 191 7.3.2 Algorithms 194 7.4 Case study 195 7.4.1 Basic parameters of the well 195 7.4.2 Simulations of kicks and blowout 195 7.4.3 Simulation of the Killing Process 198 References 203 Author Index 211 Subject Index 213