Reservoir Fluid Fundamentals Reservoir Brine Basic Workflow Exercise Review Brine Density at Standard Conditions B C D E F Salinity 120,000 [ppm] 120000 [ppm] 4 Pressure of Interest 2,250 [psia] 15484.8 [kpa.a] 5 Temperature of Interest 155 [degf] 68. [degc] 6 Solution Gas Oil Ratio 505 [scf/stb] 90.00 [sm /sm ] Calculate the density of this oilfield water at standard conditions. 1
Brine Density at Standard Conditions Brine Density at Standard Conditions 67.8617 [lb/scf] 1087.04 [kg/sm ] Brine Density at Standard Conditions Brine Density at Standard Conditions =x0rsc(c/10000) [lb/cuft] Conversion kg lb 1000 62.428 m scf This answer uses the McCain correlation, but most correlations give similar answers at standard conditions. No corrections for pressure or temperature needed. Watch your salinity units. 2
Brine Formation Volume Factor J K L M N Salinity 150,000 [ppm] 150000 [ppm] 4 Pressure of Interest 2,750 [psia] 18925.5 [kpa.a] 5 Temperature of Interest 185 [degf] 85.00 [degc] 6 Solution Gas Oil Ratio 505 [scf/stb] 90.00 [sm /sm ] 7 Brine Density at Standard Conditions 69.072 [lb/cuft] 1110.20 [kg/m ] Brine Formation Volume Factor Calculate the formation volume factor of this water at the pressure and temperature of interest using the McCain correlation. Brine Formation Volume Factor 1.029464 [bbl/stb] 1.029464 [m /sm ]
Brine Formation Volume Factor Brine Formation Volume Factor =x0bw(k4,k5) [bbl/stb] Conversion m bbl B B w w sm stb 1 p psia p kpa 0.1450778 T F T K 9 5459.68 T C T K 27.15 The McCain correlation only uses pressure and temperature to calculate the formation volume factor. Brine Density at Reservoir Conditions R S T U V Salinity 120,000 [ppm] 120000 [ppm] 4 Pressure of Interest,250 [psia] 2266.2 [kpa.a] 5 Temperature of Interest 165 [degf] 7.89 [degc] 6 Solution Gas Oil Ratio 505 [scf/stb] 90.00 [sm /sm ] 7 Brine Density at Standard Conditions 67.8617 [lb/cuft] 1087.04 [kg/m ] 8 Brine Formation Volume Factor 1.02197 [bbl/stb] 1.02197 [m /sm ] Calculate the density of this brine at reservoir conditions. 4
Brine Density at Reservoir Conditions Brine Density at Reservoir Conditions 66.4027 [lb/cuft] 106.67 [kg/m ] Brine Density at Reservoir Conditions Brine Density at Reservoir Conditions =S7/S8 [lb/cuft] Conversion kg lb 1000 62.428 m scf m bbl B 1 w B w sm stb Brine density can be calculated with reasonable accuracy by dividing the density at standard conditions by the formation volume factor. 5
Brine Viscosity at Reservoir Conditions Z AA AB AC AD Salinity 150,000 [ppm] 150000 [ppm] 4 Pressure of Interest 2,250 [psia] 15484.8 [kpa.a] 5 Temperature of Interest 195 [degf] 90.56 [degc] 6 Solution Gas Oil Ratio 505 [scf/stb] 90.00 [sm /sm ] 7 Brine Density at Standard Conditions 69.072 [lb/cuft] 1110.20 [kg/m ] Calculate the viscosity of the brine at conditions of interest using the McCain correlation. Brine Viscosity at Reservoir Conditions Brine Viscosity at Reservoir Conditions 0.515 [cp] 0.515 [mpa.s] 6
Brine Viscosity at Reservoir Conditions Brine Viscosity at Reservoir Conditions =x0ub(aa4,aa5,aa/10000) [cp] Conversion mpa.s cp 1 w w p psia p kpa 0.1450778 T F T K 9 5459.68 T C T K 27.15 Brine viscosity is a function of pressure, temperature and salinity. Temperature is not absolute. Salinity is in weight percent. Solution Gas-Brine Ratio AH AI AJ AK AL Salinity 120,000 [ppm] 120000 [ppm] 4 Pressure of Interest 2,750 [psia] 18925.5 [kpa.a] 5 Temperature of Interest 175 [degf] 79.44 [degc] 6 Solution Gas Oil Ratio 505 [scf/stb] 90.00 [sm /sm ] 7 Brine Density at Standard Conditions 67.8617 [lb/cuft] 1087.04 [kg/m ] Calculate how much gas dissolves in this brine at the pressure and temperature of interest using the McCain Correlation. 7
Solution Gas-Brine Ratio Solution Gas Brine Ratio 8.2098 [scf/stb] 1.4622 [sm /sm ] Solution Gas-Brine Ratio Solution Gas Brine Ratio =x0gwr(ai4,ai5,ai/10000) [scf/stb] Conversion sm scf R R 5.61458 sw sw sm stb p psia p kpa 0.1450778 T F T K 9459.68 T C T K 27.15 Temperature is not in absolute units. Salinity is in weight percent. 8
Bubble Point Pressure Reservoir Fluid Fundamentals Black Oil Fluid Basic Workflow Exercise Review B C D E F Separator Gas Gravity 0.625 [1/air] 0.625 [1/air] 4 Stock Tank Oil Gravity 28 [ o API] 28 [ o API] 5 Separator Gas/Stock Tank Oil Ratio 600 [scf/stb] 106.86 [sm /sm ] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Temperature 200 [degf] 9. [degc] Calculate the bubble point of this black oil using the Vazquez and Beggs correlation. 9
Bubble Point Pressure Bubble Point Pressure 4082.41 [psia] 28094.9 [kpa.a] Bubble Point Pressure Bubble Point Pressure =vasq_pb(c4,c,c5,c8) [psia] Surface gas correction cannot be applied as there is no data on separator conditions. Conversion p 0.1450778 b kpa p b psi scf sm R 5.61458 s stb sm T F T K 9 5459.68 T C T K 27.15 10
Bubble Point Formation Volume Factor J K L M N Separator Gas Gravity 0.675 [1/air] 0.675 [1/air] 4 Stock Tank Oil Gravity [ o API] [ o API] 5 Separator Gas/Stock Tank Oil Ratio 600 [scf/stb] 106.86 [sm /sm ] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Temperature 200 [degf] 9. [degc] 9 Bubble Point Pressure 14.9 [psia] 22809.4 [kpa.a] Calculate the formation volume factor at bubble point for this oil using the Vazquez and Beggs correlation. Bubble Point Formation Volume Factor Bubble Point Formation Volume Factor 1.60980 [bbl/stb] 1.60980 [m /sm ] 11
Bubble Point Formation Volume Factor Bubble Point Formation Volume Factor =vasq_bob(k4,k,k5,k8) [bbl/stb] Formation volume factors for black oils are usually between one and two. Bubble Point Density Conversion m bbl B 1 ob Bob sm stb scf sm R R 5.61458 s s stb sm T F T K 9 5459.68 T C T K 27.15 R S T U V Separator Gas Gravity 0.625 [1/air] 0.625 [1/air] 4 Stock Tank Oil Gravity 8 [ o API] 8 [ o API] 5 Separator Gas/Stock Tank Oil Ratio 600 [scf/stb] 106.86 [sm /sm ] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Temperature 200 [degf] 9. [degc] 9 Bubble Point Pressure 05.26 [psia] 20888.5 [kpa.a] 10 Bubble Point Formation Volume Factor 1.807 [bbl/stb] 1.807 [m /sm ] Calculate the density of this oil at bubble point pressure. 12
Bubble Point Density Bubble Point Oil Density 41.498 [lb/cuft] 66.801 [kg/m ] Bubble Point Density Bubble Point Oil Density =(62.428*api2sgo(S4)+(28. 966*S*S5*S6/(5.61458*1 0.72*(459.68+S7))))/S10 [lb/cuft] Calculate the mass of one unit of stock tank oil and the gas that is dissolved in it at bubble point pressure and reservoir temperature. Then divide by the formation volume factor at that pressure and temperature. Conversion scf sm R 5.61458 s Rs stb sm T F T K 9 5459.68 T C T K 27.15 p kpa p psi 0.1450778 sc sc m bbl B B 1 ob ob sm stb g lb M M 1 w w g mol lb mol kg lb 1000.0 o o m ft 62.428 1
Bubble Point Oil Viscosity Z AA AB AC AD Separator Gas Gravity 0.675 [1/air] 0.675 [1/air] 4 Stock Tank Oil Gravity 28 [ o API] 28 [ o API] 5 Separator Gas/Stock Tank Oil Ratio 600 [scf/stb] 106.86 [sm /sm ] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Temperature 200 [degf] 9. [degc] 9 Bubble Point Pressure 805.02 [psia] 26185.9 [kpa.a] 10 Bubble Point Formation Volume Factor 1.192 [bbl/stb] 1.192 [m /sm ] 11 Bubble Point Density 46.156 [lb/cuft] 79.5 [kg/m ] Bubble Point Oil Viscosity Calculate the oil viscosity at bubble point using the Beggs and Robinson correlation. Bubble Point Oil Viscosity 0.71251 [cp] 0.71251 [mpa.s] 14
Bubble Point Oil Viscosity Bubble Point Oil Viscosity =begg_uob(begg_uod(aa4,aa8),aa5) [cp] This is a two step calculation. The viscosity of the dead oil is calculated first, then it is used to calculate the live oil viscosity. Separator Gas/Stock-Tank Oil Ratio Conversion mpa. s cp 1 o o R stb sm scf sm R s s 5.61458 T F T K 9 5459.68 T C T K 27.15 AH AI AJ AK AL Separator Gas Gravity 0.625 [1/air] 0.625 [1/air] 4 Stock Tank Oil Gravity [ o API] [ o API] 5 Reservoir Pressure 000 [psia] 54.2 [kpa.a] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Temperature 200 [degf] 9. [degc] Calculate how much gas will dissolve in this oil at reservoir conditions using the Vazquez and Beggs correlation. 15
Separator Gas/Stock-Tank Oil Ratio Separator Gas/Stock Tank Oil Ratio 49.58 [scf/stb] 87.90 [sm /sm ] Separator Gas/Stock-Tank Oil Ratio Separator Gas/Stock Tank Oil Ratio =vasq_rsb(ai4,ai,ai5,ai8) [scf/stb] Use the separator gas and stock tank oil properties, as this is what the authors designed the correlation to use. Temperature is relative, not absolute. Conversion sm scf R 5.61458 s Rs sm stb p psia p kpa 0.1450778 T F T K 9 5459.68 T C T K 27.15 16
Dew Point Pressure Reservoir Fluid Fundamentals Gas Condensate and Volatile Oil Fluids Basic Workflows Exercise Review B C D E F Separator Gas Specific Gravity 0.7000 [1/air] 0.7000 [1/air] 4 Separator Pressure 50.0 [psig] 2408.7 [kpa.g] 5 Separator Temperature 100.0 [degf] 7.78 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Stock Tank Gas Specific Gravity 1.2481 [1/air] 1.2481 [1/air] 9 Stock Tank Oil Specific Gravity 52.0 [ o API] 52.0 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 225.9 [scf/stb] 40.2 [sm /sm ] 11 Stock Tank Oil/Separator Gas Ratio 200.0 [stb/mmscf] 1.1229E 0 [sm /sm ] 12 Surface Gas Gravity 0.727 [1/air] 0.727 [1/air] 1 Surface Gas/Stock Tank Oil Ratio 5225.9 [scf/stb] 91 [sm /sm ] 14 Stock Tank Oil Apparent Molecular Mass 11.97 [lb/mol] 11.97 [g/mol] 15 Reservoir Gas Specific Gravity 1.2198 [1/air] 1.2198 [1/air] Calculate the dew point pressure of this gas condensate using the Ovalle correlation. 17
Dew Point Pressure Dew Point Pressure 5,29.81 [psia] 641.7 [kpa.a] Dew Point Pressure Dew Point Pressure =oval_pd(1000*1000/c11,c9,c15) [psia] Conversion p kpa p psi 0.1450778 d d sm scf R R s s stb sm 5.61458 Ovalle used the separator-gas/stock-tank oil ratio as a correlating factor. Ovalle used reservoir gas gravity as a correlating parameter. 18
Stock-Tank Oil/Separator Gas Ratio at Pressure of Interest J K L M N Separator Gas Specific Gravity 0.7000 [1/air] 0.7000 [1/air] 4 Separator Pressure 250.0 [psig] 1720.5 [kpa.g] 5 Separator Temperature 100.0 [degf] 7.78 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Stock Tank Gas Specific Gravity 1.2966 [1/air] 1.2966 [1/air] 9 Stock Tank Oil Specific Gravity 54.0 [ o API] 54.0 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 17.2 [scf/stb] 0.84 [sm /sm ] 11 Stock Tank Oil/Separator Gas Ratio 200.0 [stb/mmscf] 1.1229E 0 [sm /sm ] 12 Surface Gas Gravity 0.7200 [1/air] 0.7200 [1/air] 1 Surface Gas/Stock Tank Oil Ratio 517.2 [scf/stb] 921 [sm /sm ] 14 Stock Tank Oil Apparent Molecular Mass 126.49 [lb/mol] 126.49 [g/mol] 15 Reservoir Gas Specific Gravity 1.2094 [1/air] 1.2094 [1/air] 16 Dew Point Pressure 4,924.0 [psia] 886.56 [kpa.a] 17 Pressure of Interest,000.0 [psia] 20645.84 [kpa.a] Calculate the stock-tank oil/separator gas ratio at the pressure of interest for this gas condensate, using the Garb correlation. Stock-Tank Oil/Separator Gas Ratio at Pressure of Interest Stock Tank Oil/Separator Gas Ratio 6.202 [stb/mmscf] 2.026E 04 [sm /sm ] at Pressure of Interest 19
Stock-Tank Oil/Separator Gas Ratio at Pressure of Interest Stock Tank Oil/Separator Gas Ratio at Pressure of Interest =garb_rv(k11,k16,k17) [stb/mmscf] Conversion sm stb R R 5.61458 1000 1000 v v sm MMscf p psia p kpa 0.1450778 Notice that the pressure of interest is NOT the dew point pressure. Two-Phase Deviation Factor R S T U V Separator Gas Specific Gravity 0.7000 [1/air] 0.7000 [1/air] 4 Separator Pressure 00.0 [psig] 2064.6 [kpa.g] 5 Separator Temperature 100.0 [degf] 7.78 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Stock Tank Gas Specific Gravity 1.27 [1/air] 1.27 [1/air] 9 Stock Tank Oil Specific Gravity 56.0 [ o API] 56.0 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 21.7 [scf/stb] 41.26 [sm /sm ] 11 Stock Tank Oil/Separator Gas Ratio at Dewpoint 200.0 [stb/mmscf] 1.1229E 0 [sm /sm ] 12 Surface Gas Gravity at Dewpoint 0.7276 [1/air] 0.7276 [1/air] 1 Surface Gas/Stock Tank Oil Ratio at Dewpoint 521.7 [scf/stb] 92 [sm /sm ] 14 Stock Tank Oil Apparent Molecular Mass 121.44 [lb/mol] 121.44 [g/mol] 15 Reservoir Gas Specific Gravity at Dewpoint 1.200 [1/air] 1.200 [1/air] 16 Dew Point Pressure 4,591.4 [psia] 1597.54 [kpa.a] 17 Pressure of Interest,000.0 [psia] 20645.84 [kpa.a] 18 Stock Tank Oil/Separator Gas Ratio at Pressure of Interest 8.62 [stb/mmscf] 2.1686E 04 [sm /sm ] 19 Surface Gas Gravity at Pressure of Interest 0.7055 [1/air] 0.7055 [1/air] 20 Surface Gas/Stock Tank Oil Ratio at Pressure of Interest 26122.5 [scf/stb] 465 [sm /sm ] 21 Reservoir Gas Specific Gravity at Pressure of Interest 0.8125 [1/air] 0.8125 [1/air] 22 Pseudo Critical Pressure of Reservoir Gas at Pressure of Interest 645.98 [psia] 4445.6 [kpa.a] 2 Pseudo Critical Temperature of Reservoir Gas at Pressure of Interest 54.68 [degf] 48.16 [degc] 24 Reservoir Temperature 250.00 [degf] 121.11 [degc] Calculate the two-phase deviation factor using the Rayes correlation for this gas condensate. 20
Two-Phase Deviation Factor Two Phase Deviation Factor 0.90277 [ ] 0.90277 [ ] Two-Phase Deviation Factor Two Phase Deviation Factor =raye_z2(s17/s22,(s24+459.68)/(s2+459.68)) [ ] Rayes used the pseudo-critical properties of the gas phase as correlation variables. Both pressures and temperatures have to be in absolute units. 21