Problem 2

A 1000-ft³ tank contains 85 STB of crude oil and 20,000 SCF of gas, all at 120°F.

When equilibrium is established (i.e., when as much gas has dissolved in the oil as

will), the pressure in the tank is 500 psia. If the solubility of the gas in the crude is

0.25 SCF/STB/psi and the deviation factor for the gas at 500 psia and 120°F is 0.90,

find the liquid formation volume factor.