Chapter 1 Introduction .......................................................... 1 1.1 The Formation of Petroleum Reservoirs ....................................... 1 1.2 Typical Characteristics of Petroleum Reservoirs ............................. 1 1.3 The Significance of Petroleum Reservoir Rock and Fluid Properties ........... 3 Chapter 2 Preamble to Petroleum Reservoir Rock Properties ....................... 5 2.1 Introduction ................................................................ 5 2.2 Coring Methods .............................................................. 6 2.2.1 Rotary Method ......................................................... 6 2.2.2 Sidewall Coring ....................................................... 6 2.2.3 High-Pressure Coring .................................................. 6 2.3 Important Issues Related to Coring Methods .................................. 7 2.4 Types of Cores .............................................................. 7 2.4.1 Whole Core ............................................................ 7 2.4.2 Core Plug ............................................................. 8 2.5 Allocation of Core Data for Measurement of Reservoir Rock Properties ........ 9 2.6 Handling of Reservoir Rock Core Samples ..................................... 9 2.7 Types of Core Tests ........................................................ 10 2.7.1 Routine or Conventional Core Analysis ................................ 10 2.7.2 Special Core Analysis ................................................ 10 References ..................................................................... 11 Chapter 3 Porosity ............................................................. 13 3.1 Significance and Definition ................................................ 13 3.2 Types of Porosities ........................................................ 13 3.2.1 Total or Absolute Porosity ........................................... 14 3.2.2 Effective Porosity ................................................... 15 3.2.3 Ineffective Porosity ................................................. 15 3.3 Classification of Porosity ................................................. 16 3.4 Parameters That Influence Porosity ......................................... 16 3.5 Laboratory Measurement of Porosity ......................................... 17 3.5.1 Porosity Determination Using Routine Core Analysis ................... 18 3.5.1.1 Bulk Volume Measurement ...................................... 18 3.5.1.2 Pore Volume Measurement ...................................... 19 3.5.1.3 Grain Volume Measurement ..................................... 21 3.6 Nonconventional Methods of Porosity Measurements ........................... 22 3.7 Averaging of Porosity ...................................................... 23 3.8 Examples of Typical Porosities ............................................. 24 Problems ....................................................................... 25 References ..................................................................... 26 Chapter 4 Absolute Permeability ................................................ 27 4.1 Significance and Definition ............................................... 27 4.2 Mathematical Expression of Permeability: Darcy's Law ...................... 27 4.3 Dimensional Analysis of Permeability and Definition of a Darcy ............ 30 4.4 Application of Darcy's Law to Inclined Flow and Radial Flow ............... 31 4.5 Averaging of Permeabilities ............................................... 33 4.5.1 Parallel Flow ....................................................... 34 4.5.2 Series Flow ......................................................... 35 4.6 Permeability of Fractures and Channels .................................... 37 4.7 Darcy's Law in Field Units ................................................ 39 4.8 Laboratory Measurement of Absolute Permeability ........................... 40 4.8.1 Measurement of Absolute Permeability Using Liquids .................. 40 4.8.2 Measurement of Absolute Permeability Using Gases .................... 42 4.9 Factors Affecting Absolute Permeability ................................... 45 4.9.1 Rock-Related Factors ................................................ 46 4.9.2 Fluid Phase-Related Factors ......................................... 47 4.9.3 Thermodynamic Factors ............................................... 49 4.9.4 Mechanical Factors .................................................. 49 4.10 Porosity and Permeability Relationships ................................... 50 4.11 Permeabilities of Different Types of Rocks ................................ 52 Problems ....................................................................... 52 References ..................................................................... 54 Chapter 5 Mechanical and Electrical Properties of Reservoir Rocks .............. 55 5.1 Introduction ............................................................... 55 5.2 Mechanical Properties ...................................................... 56 5.2.1 Stress ............................................................... 56 5.2.2 Strain ............................................................... 56 5.2.3 The Stress-Strain Relationship ....................................... 57 5.2.3.1 Factors Affecting the Stress-Strain Relationship ............. 58 5.2.4 Rock Strength ........................................................ 59 5.2.5 Rock Mechanics Parameters ............................................ 59 5.2.5.1 Poisson's Ratio .............................................. 59 5.2.5.2 Young's Modulus .............................................. 60 5.2.5.3 Modulus of Rigidity .......................................... 61 5.2.5.4 Bulk Modulus ................................................. 61 5.2.6 Laboratory Measurement of Rock Strength .............................. 61 5.2.6.1 Triaxial Cell ................................................ 62 5.2.7 Reservoir Rock Compressibility ....................................... 64 5.2.7.1 Empirical Correlations of Formation Compressibility .......... 66 5.3 Electrical Properties ...................................................... 66 5.3.1 Fundamental Concepts and the Archie Equation ........................ 67 5.3.1.1 Formation Factor ............................................. 67 5.3.1.2 Tortuosity ................................................... 68 5.3.1.3 Cementation Factor ........................................... 68 5.3.1.4 Resistivity Index ............................................ 68 5.3.2 Effect of Wettability on Electrical Properties ....................... 71 5.3.3 Effect of Clay on Electrical Properties .............................. 73 Problems ....................................................................... 75 References ..................................................................... 77 Chapter 6 Fluid Saturation ..................................................... 79 6.1 Significance and Definition ................................................ 79 6.2 Distribution of Fluid Saturation in a Petroleum Reservoir .................. 80 6.3 Definition and Mathematical Expressions for Fluid Saturation ............... 80 6.4 Reservoir Rock Samples Used for Fluid Saturation Determination ............. 82 6.5 Laboratory Measurement of Fluid Saturation ................................. 83 6.5.1 Retort Distillation .................................................. 84 6.5.2 Dean-Stark Extraction ................................................ 86 6.6 Assessing the Validity of Fluid Saturation Data Measured on the Plug-End Trim for the Core Plug Sample .............................................. 88 6.7 Special Types of Fluid Saturations ......................................... 89 6.7.1 Critical Gas Saturation .............................................. 90 6.7.2 Residual Oil Saturation .............................................. 90 6.7.3 Irreducible Water Saturation ......................................... 93 6.8 Saturation Averaging ....................................................... 94 6.9 Factors Affecting Fluid Saturation Determination ........................... 95 6.9.1 Effect of Drilling Muds on Fluid Saturation .......................... 95 6.9.2 Effect of Fluid Expansion on Fluid Saturation ........................ 97 6.9.3 Combined Effects of Mud Filtrate Invasion and Fluid Expansion on Fluid Saturation .................................................. 98 6.9.4 Mitigation of Mud Filtrate Invasion and Fluid Expansion Effects on Fluid Saturation ................................................. 100 6.9.4.1 Measures That Avoid or Account for Mud Filtrate Invasion .... 101 6.9.4.2 Measures That Avoid or Account for Fluid Expansion .......... 104 Problems ...................................................................... 106 References .................................................................... 107 Chapter 7 Interfacial Tension and Wettability ................................. 109 7.1 Introduction and Fundamental Concepts ..................................... 109 7.2 Interfacial and Surface Tension ........................................... 110 7.2.1 Effect of Pressure and Temperature on Interfacial Tension and Surface Tension ................................................. 112 7.2.2 Laboratory Measurement of Interfacial Tension ....................... 115 7.3 Wettability ............................................................... 116 7.4 Fundamental Concepts of Wettability ....................................... 117 7.5 A Discussion on Practical Aspects of Wettability .......................... 121 7.5.1 Classification/Types of Wettability ................................. 122 7.5.1.1 Water-Wet ................................................... 122 7.5.1.2 Oil-Wet ..................................................... 122 7.5.1.3 Intermediate Wet ............................................ 122 7.5.1.4 Fractional Wettability ...................................... 123 7.5.1.5 Mixed Wettability ........................................... 123 7.6 Measurement of Reservoir Rock Wettability ................................. 123 7.6.1 Contact Angle Measurement ........................................... 124 7.6.1.1 Effect of Pressure and Temperature on Contact Angles ........ 126 7.6.2 Core Samples for Amott Test and USBM Methods ........................ 126 7.6.3 Amott Test .......................................................... 128 7.6.3.1 Modification of the Amott Test (Amott-Harvey Test) .......... 130 7.6.4 USBM Method ......................................................... 131 7.7 Factors Affecting Wettability ............................................. 133 7.7.1 Composition of the Reservoir Oil .................................... 133 7.7.2 Composition of the Brine ............................................ 134 7.7.3 Reservoir Pressure and Temperature .................................. 135 7.7.4 Depth of the Reservoir Structure .................................... 136 7.8 Relationship between Wettability and Irreducible Water Saturation and Residual Oil Saturation ............................................... 137 7.8.1 Wettability and Irreducible Water Saturation ........................ 137 7.8.2 Wettability and Residual Oil Saturation ............................. 138 Problems ...................................................................... 140 References .................................................................... 141 Chapter 8 Capillary Pressure .................................................. 145 8.1 Introduction ............................................................. 145 8.2 Basic Mathematical Expression of Capillary Pressure ...................... 146 8.3 The Rise of Liquid in Capillaries ........................................ 147 8.4 Dependence of Capillary Pressure On Rock and Fluid Properties ............ 150 8.5 Capillary Pressure and Saturation History ................................ 151 8.6 Laboratory Measurement of Capillary Pressure ............................. 153 8.6.1 Leverett's Capillary Pressure Experiments .......................... 154 8.6.2 Porous Diaphragm Method ............................................ 156 8.6.3 Mercury Injection Method ........................................... 157 8.6.4 Centrifuge Method .................................................. 159 8.7 Characteristics of Capillary Pressure Curves ............................. 160 8.7.1 Saturation Scale ................................................... 161 8.7.2 Pressure Scale ..................................................... 161 8.7.3 Capillary Hysterisis ............................................... 162 8.7.4 Capillary Pressure and Permeability ................................ 163 8.8 Converting Laboratory Capillary Pressure Data to Reservoir Conditions .... 163 8.9 Averaging Capillary Pressure: The J Function ............................. 166 8.10 Calculation of Permeability from Capillary Pressure ...................... 168 8.11 Effect of Wettability on Capillary Pressure .............................. 170 8.12 Practical Application of Capillary Pressure .............................. 172 8.12.1 Pore Size Distribution ............................................ 173 8.12.2 Pore Throat Sorting ............................................... 176 8.12.3 Connate Water Saturation .......................................... 176 8.12.4 Zonation, Fluid Contacts, and Initial Saturation Distribution in a Reservoir .................................................... 177 8.12.4.1 Free Water Level ......................................... 178 8.12.4.2 Oil-Water Contact ........................................ 179 8.12.4.3 Transition Zone .......................................... 179 8.12.4.4 Oil Pay Zone or Clean Oil Zone ........................... 180 8.12.4.5 Fluid Saturation in the Gas Zone ......................... 180 Problems ...................................................................... 181 References .................................................................... 182 Chapter 9 Relative Permeability ............................................... 185 9.1 Fundamental Concepts of Relative Permeability ............................ 185 9.2 Mathematical Expressions for Relative Permeability ....................... 186 9.3 Salient Features of Gas-Oil and Water-Oil Relative Permeability Curves ... 187 9.3.1 The End-Point Fluid Saturations .................................... 189 9.3.2 The Base Permeabilities ............................................ 189 9.3.3 End-Point Permeabilities and Relative Permeability Curves .......... 189 9.3.3.1 Gas-Oil Relative Permeability Curves ....................... 190 9.3.3.2 Oil-Water Relative Permeability Curves ..................... 190 9.3.4 The Direction of the Relative Permeability Curves .................. 192 9.4 Laboratory Measurement of Relative Permeability .......................... 192 9.4.1 Flowchart for Relative Permeability Measurements ................... 193 9.4.2 Core Plug Samples Used in Relative Permeability Measurements ....... 195 9.4.3 Displacement Fluids and Test Conditions ............................ 196 9.4.3.1 Room Condition Tests ....................................... 196 9.4.3.2 Partial Reservoir Condition Tests .......................... 196 9.4.3.3 Reservoir Condition Tests .................................. 197 9.4.4 Establishment of Initial Water Saturation .......................... 197 9.4.4.1 Preserved Core Plug Samples ................................ 197 9.4.4.2 Cleaned Core Plug Samples .................................. 198 9.4.5 Determination of Base Permeability ................................. 198 9.4.6 Displacement Apparatus for Relative Permeability ................... 200 9.4.7 Steady-State Technique ............................................. 201 9.4.8 Unsteady-State Technique ........................................... 204 9.4.8.1 Buckley-Leverett to Welge to Johnson-Bossler-Naumann ....... 205 9.4.8.2 Relative Permeabilities from the Alternate Method .......... 217 9.4.9 Capillary End Effect ............................................... 218 9.5 Determination of Relative Permeability from Capillary Pressure Data ...... 220 9.6 Factors Affecting Relative Permeability Measurements ..................... 222 9.6.1 Effect of Fluid Saturation, History of Saturation, and Initial Water Saturation ................................................... 223 9.6.2 Effect of Wettability on Relative Permeability ..................... 225 9.6.3 Effect of Rock Pore Structure ...................................... 226 9.6.4 Effect of Overburden Stress (Confining Stress) ..................... 227 9.6.5 Effect of Clay Content and Movement of Fines ....................... 228 9.6.6 Effect of Temperature .............................................. 228 9.6.7 Effect of Interfacial Tension, Viscosity, and Flow Velocity ........ 228 9.7 Peculiarities of Relative Permeability Data .............................. 230 9.8 Assessing the Validity of Relative Permeability Data and Determination of Corey Exponents ....................................................... 232 9.9 Significance of Relative Permeability Data ............................... 234 9.9.1 Example of Practical Application of Relative Permeability Data ..... 235 9.10 Three-Phase Relative Permeability ........................................ 237 9.10.1 Representation of Three-Phase Relative Permeability Data .......... 237 9.10.2 Empirical Models for Three-Phase Relative Permeability ............ 239 Problems ...................................................................... 241 References .................................................................... 244 Chapter 10 Introduction to Petroleum Reservoir Fluids ......................... 247 10.1 Introduction ............................................................. 247 10.2 Chemistry of Petroleum ................................................... 247 10.2.1 Alkanes ........................................................... 248 10.2.2 Alkenes ........................................................... 249 10.2.3 Alkynes ........................................................... 250 10.2.4 Cycloaliphatics ................................................... 250 10.2.5 Aromatics ......................................................... 250 10.2.6 Nonhydrocarbons in Reservoir Fluids ............................... 251 10.3 The Solid Components of Petroleum ........................................ 251 10.3.1 Gas Hydrates ...................................................... 251 10.3.2 Waxes ............................................................. 252 10.3.3 Asphaltenes ....................................................... 252 10.3.4 Diamondoids ....................................................... 252 10.4 Classification of Reservoir Gases and Oils ............................... 252 10.4.1 Chemical Classification of Reservoir Oils or Crude Oils ........... 253 10.4.2 Physical Classification of Crude Oils ............................. 253 10.5 Five Reservoir Fluids .................................................... 254 10.6 Formation Waters ......................................................... 255 Reference ..................................................................... 255 Chapter 11 Introduction to Phase Behavior ..................................... 257 11.1 Introduction ............................................................. 257 11.2 Definition of Terms Used in Phase Behavior ............................... 258 11.2.1 Phase ............................................................. 258 11.2.2 Pressure, Temperature, and Intermolecular Forces .................. 258 11.2.3 Equilibrium ....................................................... 258 11.2.4 Component and Composition ......................................... 258 11.2.5 Distinction between Gases and Liquids ............................. 259 11.2.6 Types of Physical Properties ...................................... 259 11.2.7 Phase Rule ........................................................ 259 11.3 Phase Behavior of a Pure Component ....................................... 260 11.3.1 Phase Diagram of a Pure Component ................................. 260 11.3.1.1 Vapor Pressure Curve ..................................... 260 11.3.1.2 Critical Point ........................................... 261 11.3.1.3 Triple Point ............................................. 262 11.3.1.4 Melting Point Curve ...................................... 262 11.3.1.5 Sublimation-Pressure Curve ............................... 262 11.3.1.6 Conditions Outside the Pc-Tc Boundary .................... 262 11.3.2 Pressure-Volume Diagram ........................................... 263 11.3.3 Density-Temperature Behavior of a Pure Component .................. 264 11.3.4 Determination of Vapor Pressure ................................... 265 11.4 Phase Behavior of Two-Component or Binary Systems ........................ 266 11.4.1 Phase Diagram of a Binary System .................................. 267 11.4.1.1 Critical Point ........................................... 267 11.4.1.2 Bubble Point and Dew Point ............................... 268 11.4.1.3 Bubble-Point and Dew-Point Curves ........................ 268 11.4.1.4 Cricondenbar and Cricondentherm .......................... 269 11.4.1.5 Retrograde Dew Point and Condensation .................... 269 11.4.1.6 Behavior of a Mixture in the Two-Phase Region ............ 269 11.4.2 Effect of Changing the System Composition ......................... 272 11.5 Phase Behavior of Multicomponent Mixtures ................................ 274 11.6 Construction of Phase Envelopes .......................................... 275 Problems ...................................................................... 276 References .................................................................... 277 Chapter 12 Phase Behavior of Petroleum Reservoir Fluids ....................... 279 12.1 Introduction ............................................................ 279 12.2 Preamble to the Phase Behavior of Petroleum Reservoir Fluids ............ 279 12.3 A Brief Description of the Plus Fraction ................................ 280 12.4 Classification and Identification of Fluid Type ......................... 281 12.5 Black Oils .............................................................. 281 12.6 Volatile Oils ........................................................... 282 12.7 Gas Condensates ......................................................... 285 12.8 Wet Gases ............................................................... 287 12.9 Dry Gases ............................................................... 288 12.10 Behavior of Petroleum Reservoir Fluids in the Two-Phase Region .......... 288 Problems ...................................................................... 291 References .................................................................... 292 Chapter 13 Sampling of Petroleum Reservoir Fluids ............................. 293 13.1 Introduction ............................................................. 293 13.2 Practical Considerations of Fluid Sampling ............................... 294 13.2.1 Well Conditioning ................................................. 294 13.3 Methods of Fluid Sampling ................................................ 296 13.3.1 Subsurface Sampling ............................................... 296 13.3.2 Wellhead Sampling ................................................. 296 13.3.3 Surface Sampling .................................................. 297 13.4 Evaluating the Representativity of Fluid Samples: Quality Checks ......... 298 13.5 Factors Affecting Sample Representativity ................................ 299 Problems ...................................................................... 301 References .................................................................... 301 Chapter 14 Compositional Analysis of Petroleum Reservoir Fluids ............... 303 14.1 Introduction ............................................................. 303 14.2 Strategy of Compositional Analysis ....................................... 303 14.2.1 Surface Samples of Separator Gas and Liquid ....................... 304 14.2.2 Blow-Down Method .................................................. 304 14.2.3 Direct Determination of Composition ............................... 304 14.3 Characteristics of Reservoir Fluid Composition ........................... 305 14.3.1 Well-Defined Components ........................................... 306 14.3.2 Pseudo Fractions .................................................. 306 14.3.3 Plus Fraction ..................................................... 306 14.4 Gas Chromatography ....................................................... 307 14.5 True Boiling-Point Distillation .......................................... 309 14.5.1 Properties of TBP Cuts and Residue ................................ 310 14.5.2 Internal Consistency of TBP Data .................................. 311 14.5.3 Properties of TBP Cuts and Generalized Data ....................... 313 14.6 Characterization of Pseudo Fractions and Residue ......................... 314 14.7 Other Nonconventional Methods of Compositional Analysis .................. 316 Problems ...................................................................... 317 References .................................................................... 318 Chapter 15 PVT Analysis and Reservoir Fluid Properties ........................ 321 15.1 Introduction ............................................................. 321 15.2 Properties of Petroleum Reservoir Fluids ................................. 322 15.2.1 Gases and Liquids ................................................. 323 15.2.2 Ideal Gases ....................................................... 323 15.2.2.1 Standard Volume ....................................... 324 15.2.3 Real Gases ........................................................ 324 15.2.3.1 Gas Density .............................................. 327 15.2.3.2 Specific Gravity ......................................... 328 15.2.4 Mixtures of Gases ................................................. 328 15.2.4.1 Apparent Molecular Weight ................................ 328 15.2.4.2 Critical Pressure and Temperature of Gas Mixtures ........ 329 15.2.4.3 Determination of Compressibility Factor of Gas Mixtures ................................................. 332 15.2.4.4 Determination of Density of Gas Mixtures ................. 334 15.2.5 Dry Gases ......................................................... 334 15.2.5.1 Formation Volume Factor .................................. 334 15.2.5.2 Coefficient of Isothermal Compressibility ................ 336 15.2.5.3 Viscosity ................................................ 336 15.2.6 Wet Gases ......................................................... 338 15.2.6.1 Recombination Cases ...................................... 338 15.2.6.2 Formation Volume Factor .................................. 342 15.2.7 Gas Condensates ................................................... 343 15.2.8 Black Oils and Volatile Oils ...................................... 343 15.2.8.1 Formation Volume Factor .................................. 344 15.2.8.2 Solution Gas-Oil Ratio or Gas Solubility ................. 345 15.2.8.3 Total Formation Volume Vactor ............................ 345 15.2.8.4 Coefficient of Isothermal Compressibility ................ 347 15.2.8.5 Viscosity ................................................ 348 15.2.8.6 Surface Tension .......................................... 349 15.2.8.7 Volatile Oils ............................................ 351 15.3 Laboratory Tests ......................................................... 351 15.3.1 PVT Equipment ..................................................... 352 15.3.2 Constant Composition Expansion .................................... 354 15.3.3 Differential Liberation ........................................... 356 15.3.4 Constant Volume Depletion ......................................... 359 15.3.4.1 Liquid Drop Out .......................................... 361 15.3.4.2 Material Balance for Condensate Composition .............. 361 15.3.4.3 Two-Phase Compressibility Factor ......................... 365 15.3.5 Separator Tests ................................................... 365 15.3.5.1 Optimum Separator Conditions ............................. 367 15.4 Adjustment of Black Oil Laboratory Data .................................. 367 15.4.1 Combination Equations ............................................. 370 15.4.1.1 Formation Volume Factor of Oil ........................... 371 15.4.1.2 Solution Gas-Oil Ratio ................................... 372 15.4.1.3 Formation Volume Factor of Gas ........................... 373 15.4.1.4 Total Formation Volume Factor ............................ 374 15.4.1.5 Coefficient of Isothermal Compressibility of Oil ......... 374 15.4.2 Composite Liberation .............................................. 374 15.5 Other Sources of Obtaining the Properties of Petroleum Reservoir Fluids Fluids ................................................................... 375 15.5.1 Empirical Correlations ............................................ 375 15.5.1.1 Standing's Empirical Correlations ........................ 376 15.5.2 Prediction of Viscosity from Compositional Data ................... 378 15.5.3 Prediction of Surface Tension ..................................... 380 Problems ...................................................................... 381 References .................................................................... 387 Chapter 16 Vapors-Liquid Equilibria ........................................... 389 16.1 Introduction ............................................................. 389 16.2 Ideal Solution Principle ................................................. 390 16.2.1 Raoult's Law ...................................................... 390 16.2.2 Dalton's Law ...................................................... 390 16.2.3 Equilibrium Ratio ................................................. 391 16.2.4 Concept of PT Flash ............................................... 391 16.2.5 Calculation of Bubble-Point Pressure .............................. 393 16.2.6 Calculation of Dew-Point Pressure ................................. 393 16.2.7 Drawbacks of the Ideal Solution Principle ......................... 394 16.3 Empirical Correlations for Calculating Equilibrium Ratios for Real Solutions ................................................................ 395 16.3.1 Wilson Equation ................................................... 395 16.3.2 Methods Based on the Concept of Convergence Pressure .............. 396 16.3.2.1 K-Value Charts ........................................... 399 16.3.2.2 Whitson-Torp Correlation ................................. 403 16.4 Equations-Of-State (EOS) Models .......................................... 404 16.4.1 Description of EOS Models ......................................... 405 16.4.1.1 van der Waals Equation of State .......................... 405 16.4.1.2 Redlich-Kwong Equation of State .......................... 409 16.4.1.3 Soave-Redlich-Kwong Equation of State .................... 410 16.4.1.4 Peng-Robinson Equation of State .......................... 411 16.4.2 Concept of Fugacity ............................................... 411 16.4.3 Application of Equations of State to Pure Components .............. 412 16.4.4 Extension of EOS Models to Mixtures ............................... 413 16.4.4.1 Determination of Equilibrium Ratios from EOS Models ...... 416 16.4.5 VLE Calculations Using EOS Models ................................. 418 16.4.5.1 Calculation of Bubble-Point Pressure ..................... 418 16.4.5.2 Calculation of Dew-Point Pressure ........................ 421 16.4.5.3 PT Flash Calculations .................................... 421 16.4.5.4 Separator Calculations ................................... 424 16.4.5.5 A Note About the Application of EOS Models to Real Reservoir Fluids ......................................... 428 16.5 Use of EOS Models in PVT Packages ........................................ 429 Problems ...................................................................... 430 References .................................................................... 431 Chapter 17 Properties of Formation Waters ..................................... 433 17.1 Introduction ............................................................. 433 17.2 Compositional Characteristics of Formation Water ......................... 434 17.3 Bubble-Point Pressure of Formation Water ................................. 435 17.4 Formation Volume Factor of Formation Water ............................... 435 17.5 Density of Formation Water ............................................... 437 17.6 Viscosity of Formation Water ............................................. 437 17.7 Solubility of Hydrocarbons in Formation Water ............................ 438 17.8 Solubility of Formation Water in Hydrocarbons ............................ 440 17.8.1 Water Content of Gaseous Hydrocarbons ............................. 441 17.8.2 Water Content of Liquid Hydrocarbons .............................. 441 17.9 Compressibility of Formation Water ....................................... 442 Problems ...................................................................... 443 References .................................................................... 444 Author Index .................................................................. 445 Subject Index ................................................................. 449