Pseudo-Critical Properties Reservoir Fluid Fundamentals Dry Gas Fluid Basic Workflow Exercise Review B C D E F 3 Separator Gas Specific Gravity 0.6300 [1/air] 0.6300 [1/air] 4 Separator Pressure 100.0 [psig] 688.2 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] Calculate the pseudo-critical properties of this dry gas using the Brown correlation. 1
Pseudo-Critical Properties Pseudo Critical Pressure 671.57 [psia] 4621.7 [kpa.a] Pseudo Critical Temperature 91.891 [degf] 68.828 [degc] Pseudo-Critical Properties Pseudo Critical Pressure =stan_pc(c3,"dry") [psia] Pseudo Critical Temperature =stan_tc(c3,"dry") [degf] Conversion p 0.145037738 pc kpa p pc psia T K T R 5 9 pc pc o T R T F 459.68 pc pc T C T K 273.15 pc pc Input for Brown correlation is specific gravity. Use the dry gas version of the correlation. Make sure you notice the unit choices required for your answer. 2
Pseudo-Reduced Properties J K L M N 3 Separator Gas Specific Gravity 0.6400 [1/air] 0.6400 [1/air] 4 Separator Pressure 100.0 [psig] 688.2 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Pressure 1250.0 [psig] 8602.4 [kpa.g] 9 Reservoir Temperature 100.0 [degf] 37.78 [degc] 10 Pseudo Critical Pressure 671.24 [psia] 4619.44 [kpa.a] 11 Pseudo Critical Temperature 88.80 [degf] 67.11 [degc] Calculate the pseudo-reduced properties for this dry gas. Pseudo-Reduced Properties Pseudo Reduced Pressure 1.8841 [ ] 1.8841 [ ] Pseudo Reduced Temperature 1.5091 [ ] 1.5091 [ ] 3
Pseudo-Reduced Properties Pseudo Reduced Pressure =(K8+K6)/K10 [ ] Pseudo Reduced Temperature =(K9+459.68)/(K11+459.68) [ ] Remember to use absolute units for both pressure and temperature. Units in the numerator and denominator need to be the same, or you calculate rubbish. Gas Deviation Factor R S T U V 3 Separator Gas Specific Gravity 0.6600 [1/air] 0.6600 [1/air] 4 Separator Pressure 100.0 [psig] 688.2 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Pressure 1550.0 [psig] 10667.0 [kpa.g] 9 Reservoir Temperature 130.0 [degf] 54.44 [degc] 10 Pseudo Reduced Pressure 2.3334 [ ] 2.3334 [ ] 11 Pseudo Reduced Temperature 1.5639 [ ] 1.5639 [ ] Calculate the gas deviation factor for this dry gas. 4
Gas Deviation Factor Gas Deviation Factor 0.83171 [ ] 0.83171 [ ] Gas Deviation Factor Gas Deviation Factor =Abou_Z(S10,S11,1) [ ] Remember that the Dranchuk and Abou-Kassem correlation is the most accurate correlation in general use. A starting guess of unity is usually a good choice for a dry gas. 5
Formation Volume Factor Z AA AB AC AD 3 Separator Gas Specific Gravity 0.6700 [1/air] 0.6700 [1/air] 4 Separator Pressure 100.0 [psig] 688.2 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Pressure 1350.0 [psig] 9290.6 [kpa.g] 9 Reservoir Temperature 120.0 [degf] 48.89 [degc] 10 Gas Deviation Factor 0.8304 [ ] 0.8304 [ ] 11 Universal Gas Constant 10.7320 [psi.cuft/mol/degr] 8.3135 [J/mol/K] 12 Air Apparent Molecular Mass 28.9660 [lb/mol] 28.9660 [g/mol] Calculate the formation volume factor for this dry gas. Formation Volume Factor Gas Formation Volume Factor 9.9779E 03 [cuft/scf ] 9.9779E 03 [m 3 /sm 3 ] Conversion 3 3 B m / sm B cuft / scf 1 g g 6
Formation Volume Factor Gas Formation Volume Factor =(AA10*(AA9+459.68)/(AA8+AA6))*(AA6/(AA7+459.68)) [cuft/scf] Remember that Bg is reservoir volume divided by surface volume. Remember that the gas deviation factor at standard conditions is usually very close to unity. Remember that pressures and temperatures have to be in absolute units. Apparent Molecular Mass AH AI AJ AK AL 3 Separator Gas Specific Gravity 0.6800 [1/air] 0.6800 [1/air] 4 Separator Pressure 100.0 [psig] 688.2 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Pressure 1650.0 [psig] 11355.2 [kpa.g] 9 Reservoir Temperature 150.0 [degf] 65.56 [degc] 10 Gas Deviation Factor 0.8370 [ ] 0.8370 [ ] 11 Universal Gas Constant 10.7320 [psi.cuft/mol/degr] 8.3135 [J/mol/K] 12 Air Apparent Molecular Mass 28.9660 [lb/mol] 28.9660 [g/mol] Calculate the apparent molecular mass of this dry gas. 7
Apparent Molecular Mass Apparent Molecular Mass 19.697 [lb/mol] 19.697 [g/mol] Apparent Molecular Mass Apparent Molecular Mass =AI3*AI12 [lb/mol] Conversion M g / g mol M lb/ lb mol 1 w w Remember that apparent molecular mass does not change unless composition changes. Remember that gas density at standard conditions is directly proportional to molecular mass. 8
In-Situ Density AP AQ AR AS AT 3 Separator Gas Specific Gravity 0.6100 [1/air] 0.6100 [1/air] 4 Separator Pressure 100.0 [psig] 688.2 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Pressure 1450.0 [psig] 9978.8 [kpa.g] 9 Reservoir Temperature 140.0 [degf] 60.00 [degc] 10 Gas Deviation Factor 0.8728 [ ] 0.8728 [ ] 11 Universal Gas Constant 10.7320 [psi.cuft/mol/degr] 8.3135 [J/mol/K] 12 Air Apparent Molecular Mass 28.9660 [lb/mol] 28.9660 [g/mol] In-Situ Density Calculate the in-situ density of this dry gas. In Situ Gas Density 4.6075 [lb/cuft] 73.806 [kg/m 3 ] 9
In-Situ Density In Situ Gas Density =AQ3*AQ12*(AQ6+AQ8)/(AQ10*AQ11*(AQ9+459.68)) [lb/cuft] Conversion kg lb 1000.0 3 3 m ft 62.428 Remember that density is mass over volume. If you utilize molecular mass, then you need a molar volume to match. Watch out for your units! In-Situ Compressibility AP AQ AR AS AT 3 Separator Gas Specific Gravity 0.6700 [1/air] 0.6700 [1/air] 4 Separator Pressure 100.0 [psig] 688.2 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Pressure 2100.0 [psig] 14452.1 [kpa.g] 9 Reservoir Temperature 145.0 [degf] 62.78 [degc] 10 Gas Deviation Factor 0.820198 [ ] 0.820198 [ ] 11 Universal Gas Constant 10.7320 [psi.cuft/mol/degr] 8.3135 [J/mol/K] 12 Air Apparent Molecular Mass 28.9660 [lb/mol] 28.9660 [g/mol] 14 Pressure 2101.0 [psig] 14459.0 [kpa.g] 15 Temperature 145.0 [degf] 62.78 [degc] 16 Gas Deviation Factor 0.820179 [ ] 0.820179 [ ] Calculate the in-situ compressibility of this dry gas. 10
In-Situ Compressibility Gas Compressibility 5.0014E 04 [1/psi] 7.2674E 05 [1/kPa] In-Situ Compressibility Gas Compressibility =(1/AY8) (1/AY10)*(AY16 AY10)/(AY14 AY8) [1/psi] Conversion c 1/ kpa c 1/ psia 0.145037738; p kpa p psia 0.145037738 g g This answer uses finite differences rather than an analytical differentiation of the gas deviation factor equation. Therefore, the smaller the p, the more accurate the answer, once we don t approach the limits of machine precision. 11
In-Situ Viscosity In-Situ Viscosity BF BG BH BI BJ 3 Separator Gas Specific Gravity 0.6300 [1/air] 0.6300 [1/air] 4 Separator Pressure 100.0 [psig] 688.2 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [degc] 6 Standard Pressure 14.7 [psia] 101.2 [kpa.a] 7 Standard Temperature 60.0 [degf] 15.56 [degc] 8 Reservoir Pressure 1300.0 [psig] 8946.5 [kpa.g] 9 Reservoir Temperature 195.0 [degf] 90.56 [degc] 10 Gas Deviation Factor 0.9113 [ ] 0.9113 [ ] 11 Universal Gas Constant 10.7320 [psi.cuft/mol/degr] 8.3135 [J/mol/K] 12 Air Apparent Molecular Mass 28.9660 [lb/mol] 28.9660 [g/mol] Calculate the in-situ viscosity of this dry gas. In Situ Gas Viscosity 1.5199E 02 [cp] 1.5199E 02 [mpa.s] 12
In-Situ Viscosity In Situ Gas Viscosity =Lee2_Ugb(Lee2_Ugd(BG3,BG9),BG3,BG8+BG6,BG9,BG10) [cp] Conversion mpa. s cp 1 Atmospheric gas viscosity is a function of specific gravity and temperature. Correction for the effect of pressure is a function of in-situ gas density in g/cc. Gas density is a function of specific gravity, pressure, temperature and gas deviation factor. 13
Reservoir Fluid Fundamentals Wet Gas Fluid Basic Workflow Exercise Review Surface Gas Gravity and Surface Gas-Stock Tank Oil Ratio B C D E F 3 Separator Gas Specific Gravity 0.6800 [1/air] 0.6800 [1/air] 4 Separator Pressure 300.0 [psig] 2064.6 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [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 1.3547 [1/air] 1.3547 [1/air] 9 Stock Tank Oil Specific Gravity 58.0 [ o API] 58.00 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 267.3 [scf/stb] 47.60 [sm 3 /sm 3 ] 11 Stock Tank Oil/Separator Gas Ratio 10.0 [stb/mmscf] 5.6146E 05 [sm 3 /sm 3 ] Calculate the surface gas gravity and surface gas-stock-tank oil ratio of this wet gas. 14
Surface Gas Gravity and Surface Gas-Stock Tank Oil Ratio Surface Gas Gravity 0.68180 [1/air] 0.68180 [1/air] Surface Gas/Stock Tank Oil Ratio 100,267 [scf/stb] 17858 [sm 3 /sm 3 ] Surface Gas Gravity and Surface Gas-Stock Tank Oil Ratio Surface Gas Gravity =(1000*1000*C3/C11+C10*C8)/(1000*1000/C11+C10) [1/air] Surface Gas/Stock Tank Oil Ratio =1000*1000/C11+C10 [scf/stb] Conversion 3 sm stb 5.61458 3.28083.28083.2808 3 sm MMscf 3.28083.28083.2808 10001000 This is a recombination on a molar basis. Since different gases have the same molar volume at standard temperature and pressure, we use standard volumes as proxies for molar quantities. It is common to use different units for separator and stock-tank gas. 15
Molar Mass Molar Mass J K L M N 3 Separator Gas Specific Gravity 0.6600 [1/air] 0.6600 [1/air] 4 Separator Pressure 300.0 [psig] 2064.6 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [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 1.3214 [1/air] 1.3214 [1/air] 9 Stock Tank Oil Specific Gravity 56.0 [ o API] 56.00 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 243.2 [scf/stb] 43.32 [sm 3 /sm 3 ] 11 Stock Tank Oil/Separator Gas Ratio 13.0 [stb/mmscf] 7.2990E 05 [sm 3 /sm 3 ] Calculate the molar mass of this stock tank oil using the Cragoe correlation. Stock Tank Oil Apparent Molecular Mass 121.44 [lb/mol] 121.44 [g/mol] 16
Molar Mass Surface Gas Gravity =6084/(K9 5.9) [lb/mol] Careful with the constants. There are many revisions to the Cragoe correlation available in the literature. This version requires specific gravity in API degrees. In-Situ Specific Gravity R S T U V 3 Separator Gas Specific Gravity 0.6800 [1/air] 0.6800 [1/air] 4 Separator Pressure 300.0 [psig] 2064.6 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [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 1.2874 [1/air] 1.2874 [1/air] 9 Stock Tank Oil Specific Gravity 54.0 [ o API] 54.00 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 221.1 [scf/stb] 39.38 [sm 3 /sm 3 ] 11 Stock Tank Oil/Separator Gas Ratio 16.0 [stb/mmscf] 8.9833E 05 [sm 3 /sm 3 ] 12 Surface Gas Gravity 0.6821 [1/air] 0.6821 [1/air] 13 Surface Gas/Stock Tank Oil Ratio 62721.1 [scf/stb] 11171 [sm 3 /sm 3 ] 14 Stock Tank Oil Apparent Molecular Mass 126.49 [lb/mol] 126.49 [g/mol] Calculate the in-situ specific gravity of this wet gas. 17
In-Situ Specific Gravity Reservoir Gas Specific Gravity 0.72866 [1/air] 0.72866 [1/air] In-Situ Specific Gravity Reservoir Gas Specific Gravity =(S12*S13+4591*api2sgo(S9))/(S13+132983*api2sgo(S9)/S14) [1/air] Remember that the values of the constants 4591 and 132983 are functions of the standard temperature and pressure, which vary from state to state, and country to country. Otherwise, this is a molar recombination of stock tank oil and surface gases. 18
Pseudo-Critical Properties Z AA AB AC AD 3 Separator Gas Specific Gravity 0.6600 [1/air] 0.6600 [1/air] 4 Separator Pressure 300.0 [psig] 2064.6 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [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 1.2527 [1/air] 1.2527 [1/air] 9 Stock Tank Oil Specific Gravity 52.0 [ o API] 52.00 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 200.7 [scf/stb] 35.75 [sm 3 /sm 3 ] 11 Stock Tank Oil/Separator Gas Ratio 10.0 [stb/mmscf] 5.6146E 05 [sm 3 /sm 3 ] 12 Surface Gas Gravity 0.6612 [1/air] 0.6612 [1/air] 13 Surface Gas/Stock Tank Oil Ratio 100200.7 [scf/stb] 17847 [sm 3 /sm 3 ] 14 Stock Tank Oil Apparent Molecular Mass 131.97 [lb/mol] 131.97 [g/mol] 15 Reservoir Gas Specific Gravity 0.6912 [1/air] 0.6912 [1/air] Pseudo-Critical Properties Calculate the pseudo-critical properties of this wet gas using the Brown Correlation. In situ Gas Pseudo Critical Pressure 664.96 [psia] 4576.3 [kpa.a] In situ Gas Pseudo Critical Temperature 78.753 [degf] 61.530 [degc] 19
Pseudo-Critical Properties In situ Gas Pseudo Critical Pressure =stan_pc(aa15,"wet") [psia] In situ Gas Pseudo Critical Temperature =stan_tc(aa15,"wet") [degf] Conversion p 0.145037738 pc kpa p pc psia T K T R 5 9 pc pc T R T F 459.68 pc pc Remember Standing built the equations to describe the graphical Brown correlation. Remember Brown had separate correlations for wet and dry gases. Mole Fractions AH AI AJ AK AL 3 Separator Gas Specific Gravity 0.6800 [1/air] 0.6800 [1/air] 4 Separator Pressure 300.0 [psig] 2064.6 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [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 1.3547 [1/air] 1.3547 [1/air] 9 Stock Tank Oil Specific Gravity 58.0 [ o API] 58.00 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 267.3 [scf/stb] 47.60 [sm 3 /sm 3 ] 11 Stock Tank Oil/Separator Gas Ratio 18.0 [stb/mmscf] 1.0106E 04 [sm 3 /sm 3 ] 12 Surface Gas Gravity 0.6832 [1/air] 0.6832 [1/air] 13 Surface Gas/Stock Tank Oil Ratio 55822.8 [scf/stb] 9942 [sm 3 /sm 3 ] 14 Stock Tank Oil Apparent Molecular Mass 116.78 [lb/mol] 116.78 [g/mol] 15 Reservoir Gas Specific Gravity 0.7335 [1/air] 0.7335 [1/air] 16 Reservoir Gas Pseudo Critical Pressure 662.11 [psia] 4556.59 [kpa.a] 17 Reservoir Gas Pseudo Critical Temperature 69.10 [degf] 56.17 [degc] Calculate the mole fractions of surface gas and stock tank oil making up this wet gas. 20
Mole Fractions Mole Fraction Surface Oil in Reservoir Gas 0.015004 [ ] 0.015004 [ ] Mole Fraction Surface Gas in Reservoir Gas 0.984996 [ ] 0.984996 [ ] Mole Fractions Mole Fraction Surface Oil in Reservoir Gas =28.966*(AI15 AI12)/(AI14 28.966*AI12) [ ] Mole Fraction Surface Gas in Reservoir Gas =1 AI31 [ ] Surface oil is defined as the hydrocarbon liquid which is stable at standard temperature and pressure. Everything else that is not aqueous is considered surface gas. The mole fractions of surface oil and surface gas have to add up to unity. 21
Formation Volume Factor AP AQ AR AS AT 3 Separator Gas Specific Gravity 0.6600 [1/air] 0.6600 [1/air] 4 Separator Pressure 300.0 [psig] 2064.6 [kpa.g] 5 Separator Temperature 80.0 [degf] 26.67 [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 1.3214 [1/air] 1.3214 [1/air] 9 Stock Tank Oil Specific Gravity 56.0 [ o API] 56.00 [ o API] 10 Stock Tank Gas/Stock Tank Oil Ratio 243.2 [scf/stb] 43.32 [sm 3 /sm 3 ] 11 Stock Tank Oil/Separator Gas Ratio 13.0 [stb/mmscf] 7.2990E 05 [sm 3 /sm 3 ] 12 Surface Gas Gravity 0.6621 [1/air] 0.6621 [1/air] 13 Surface Gas/Stock Tank Oil Ratio 77166.3 [scf/stb] 13744 [sm 3 /sm 3 ] 14 Stock Tank Oil Apparent Molecular Mass 121.44 [lb/mol] 121.44 [g/mol] 15 Reservoir Gas Specific Gravity 0.6995 [1/air] 0.6995 [1/air] 16 Reservoir Gas Pseudo Critical Pressure 664.41 [psia] 4572.40 [kpa.a] 17 Reservoir Gas Pseudo Critical Temperature 76.83 [degf] 60.46 [degc] 18 Mole Fraction Surface Gas in Reservoir Gas 0.989404 [ ] 0.989404 [ ] 19 Reservoir Pressure 2000.0 [psia] 13763.9 [kpa.a] 20 Reservoir Temperature 150.0 [degf] 65.56 [degc] 21 Reservoir Gas Deviation Factor 0.8233 [ ] 0.8233 [ ] Calculate the formation volume factor of this wet gas. Formation Volume Factor Formation Volume Factor 7.0991E 03 [cuft/scf] 7.0991E 03 [m 3 /sm 3 ] 22
Formation Volume Factor Formation Volume Factor =(AQ21*(AQ20+459.68)/AQ19)*(AQ6/(AQ7+459.68)) [cuft]/[scf] Conversion 3 3 B m / sm B cuft / scf 1 g g Remember that all the gas in the reservoir does not remain in the vapor phase at the surface for wet gases. 23
Reservoir Fluid Fundamentals Under-Saturated Oil Basic Workflow Under-Saturated Compressibility Exercise Review B C D E F 3 Separator Gas Gravity 0.7 [1/air] 0.7 [1/air] 4 Stock Tank Oil Gravity 35 [ o API] 35 [ o API] 5 Separator Gas/Stock Tank Oil Ratio 500 [scf/stb] 89.05 [sm 3 /sm 3 ] 6 Bubble Point Pressure 2260.7 [psia] 15558.16 [kpa.a] 7 Reservoir Temperature 125 [degf] 51.67 [degc] 8 Bubble Point Formation Volume Factor 1.2714 [bbl/stb] 1.2714 [m 3 /sm 3 ] 9 Bubble Point Density 54.4376 [lb/cuft] 872.01 [kg/m 3 ] 10 Bubble Point Viscosity 1.042 [cp] 1.042 [mpa.s] 11 Reservoir Pressure 5000 [psia] 34409.73 [kpa.a] Calculate the under-saturated compressibility of this oil using the Vazquez and Beggs Correlation. 24
Under-Saturated Compressibility Undersaturated Oil Compressibility 5.6647E 06 [1/psi] 8.2312E 07 [1/kPa] Under-Saturated Compressibility Undersaturated Oil Compressibility =vasq_co(c11,c7,c3,c4,c5) [1/psi] Conversion c 1/ 1/ 0.145037738 o kpa c o psia 3 3 R scf / stb R sm / sm 5.61458 s s T F T K 9 5 459.68 p psia p kpa 0.145037738 Under-saturated oil compressibility is NOT independent of pressure, so that the pressure of interest is used in the calculation. 25
Formation Volume Factor J K L M N 3 Separator Gas Gravity 0.7 [1/air] 0.7 [1/air] 4 Stock Tank Oil Gravity 30 [ o API] 30 [ o API] 5 Separator Gas/Stock Tank Oil Ratio 500 [scf/stb] 89.05 [sm 3 /sm 3 ] 6 Bubble Point Pressure 2529.1 [psia] 17405.19 [kpa.a] 7 Reservoir Temperature 125 [degf] 51.67 [degc] 8 Bubble Point Formation Volume Factor 1.2574 [bbl/stb] 1.2574 [m 3 /sm 3 ] 9 Bubble Point Density 55.7043 [lb/cuft] 892.30 [kg/m 3 ] 10 Bubble Point Viscosity 1.446 [cp] 1.446 [mpa.s] 11 Reservoir Pressure 5000 [psia] 34409.73 [kpa.a] 12 Undersaturated Oil Compressibility 5.5386E 06 [1/psi] 8.0480E 07 [1/kPa] Formation Volume Factor Calculate the formation volume factor of this under-saturated oil using the classic formula. Undersaturated Oil Formation Volume Factor 1.240313 [bbl/stb] 1.240313 [m 3 /sm 3 ] 26
Formation Volume Factor Undersaturated Oil Formation Volume Factor =K8*EXP( K12*(K11 K6)) [bbl/stb] Viscosity Conversion c 1/ 1/ 0.145037738 o kpa c o psia p psia p kpa 0.145037738 3 3 B m / sm B bbl / stb 1.0 o o R S T U V 3 Separator Gas Gravity 0.7 [1/air] 0.7 [1/air] 4 Stock Tank Oil Gravity 35 [ o API] 35 [ o API] 5 Separator Gas/Stock Tank Oil Ratio 500 [scf/stb] 89.05 [sm 3 /sm 3 ] 6 Bubble Point Pressure 2260.7 [psia] 15558.16 [kpa.a] 7 Reservoir Temperature 125 [degf] 51.67 [degc] 8 Bubble Point Formation Volume Factor 1.2714 [bbl/stb] 1.2714 [m 3 /sm 3 ] 9 Bubble Point Density 54.4376 [lb/cuft] 872.01 [kg/m 3 ] 10 Bubble Point Viscosity 1.042 [cp] 1.042 [mpa.s] 11 Reservoir Pressure 5000 [psia] 34409.73 [kpa.a] Calculate the viscosity of this under-saturated oil using the Vazquez & Beggs correlation. 27
Viscosity Undersaturated Oil Viscosity 1.4411 [cp] 1.4411 [mpa.s] Viscosity Undersaturated Oil Viscosity =begg_uou(s10,s6,s11) [cp] Conversion mpa. s cp 1 ou ou p psia p kpa 0.145037738 This viscosity correlation does not need any additional fluid properties, it uses the bubble point oil viscosity and corrects it for pressure. 28
Under-Saturated Density Z AA AB AC AD 3 Separator Gas Gravity 0.6 [1/air] 0.6 [1/air] 4 Stock Tank Oil Gravity 30 [ o API] 30 [ o API] 5 Separator Gas/Stock Tank Oil Ratio 500 [scf/stb] 89.05 [sm 3 /sm 3 ] 6 Bubble Point Pressure 2911.9 [psia] 20039.56 [kpa.a] 7 Reservoir Temperature 125 [degf] 51.67 [degc] 8 Bubble Point Formation Volume Factor 1.2613 [bbl/stb] 1.2613 [m 3 /sm 3 ] 9 Bubble Point Density 55.7883 [lb/cuft] 893.64 [kg/m 3 ] 10 Bubble Point Viscosity 1.446 [cp] 1.446 [mpa.s] 11 Reservoir Pressure 6000 [psia] 41291.68 [kpa.a] 12 Undersaturated Oil Compressibility 4.8122E 06 [1/psi] 6.9925E 07 [1/kPa] 13 Undersaturated Oil Formation Volume Factor 1.242723 [bbl/stb] 1.242723 [m 3 /sm 3 ] Under-Saturated Density Calculate the under-saturated density of this oil at reservoir pressure. Undersaturated Oil Density 56.624 [lb/cuft] 907.02 [kg/m 3 ] 29
Under-Saturated Density Undersaturated Oil Density =AA9*AA8/AA13 [lb/cuft] Conversion / / 1.0 3 3 Bo m sm Bo bbl stb 3 kg m lb cuft o o / / 62.428/1000.0 Under-saturated oil density can be calculated with reasonable accuracy by dividing the density at bubble point by the formation volume factor at elevated pressure and then multiplying by the formation volume factor at bubble point conditions. 30