Page 106 - PVT Property Correlations

84 PVT Property Correlations

R 3 stock-tank GOR (scf/STB)
R t total producing gas oil ratio (scf/STB)
S wi initial water saturation (fraction)

T s1 primary separator temperature ( F)

T s2 secondary separator temperature ( F)
V eq vapor equivalent of primary separator liquid (scf/STB)
[ porosity (fraction)
specific gravity of primary separator gas (air 5 1.0)
γ 1
γ 2 specific gravity of secondary separator gas (air 5 1.0)
γ 3 specific gravity of stock-tank gas (air 5 1.0)
γ gw reservoir gas specific gravity (water 5 1.0)
γ o specific gravity of stock-tank liquid (water 5 1.0)

REFERENCES
Dranchuk, P.M., Abou-Kassem, J.H., 1975. Calculation of z-factors for natural gases using equa-
tions of state, J. Can. Pet. Tech., 14, pp. 34 36.
Gold, D.K., McCain Jr., W.D., Jennings, J.W., 1989. An improved method for the determination
of the reservoir-gas specific gravity for retrograde gases, J. Pet. Tech., 41, pp. 747 752.
Peneloux, A., Rauzy, E., Freze, R., 1982. A consistent correction for Redlich Kwong Soave
volumes, Fluid Phase Equilib., 8, pp. 7 23.
Piper, L.D., McCain Jr., W.D., Corredor, J.H., 1993. Compressibility factors for naturally occur-
ring petroleum gases. In: Paper SPE 26668 Presented at the 1993 SPE Technical Conference
and Exhibition, Houston, October 3 6.
Soave, G., 1972. Equilibrium constants from a modified Redlich Kwong equation of state,
Chem. Eng. Sci., 27, pp. 1197 1203.

FURTHER READING
Beggs, H.D., 1984. Gas Production Operations. OGCI Publications, Tulsa, OK.
Craft, B.C., Hawkins, M.F., Terry, R.E., 1991. Applied Petroleum Reservoir Engineering.
Prentice Hall, Englewood Cliffs, NJ, USA.
McCain Jr., W.D., 1990. The Properties of Petroleum Fluids, 2nd ed. PennWell Books, Tulsa,
OK, USA.
McCain Jr., W.D., Piper, L.D., 1994. Reservoir gases exhibit subtle differences. Pet. Eng. Int.
(March), pp. 45 46.
Moses, P.L., 1986. Engineering applications of phase behavior of crude oil and condensate sys-
tems, J. Pet. Tech., 38, p. 715.

PROBLEMS
4.1 Two sets of gas samples were selected for further analysis from two
exploratory wells. Identify the fluid type for each sample. Also, calcu-
late the heating value of the two gas samples.