Gas Formation Volume Factor (GFVF) as a function of Reservoir Pressure:
Isothermal Compressibility below Bubble-Point (BP) Pressure:
Since the conventional isothermal compressibility on crude oil ‘below BP pressure’ would lead to negative compressibility (as the volume of crude oil mitigates with pressure decline), the shrinkage effect of saturated-oil (variation of oil formation volume factor as a function of reservoir pressure) and the expansion effect of the gas coming out of solution (variation of solution GOR & GVFV as a function of reservoir pressure) needs to be considered explicitly.
If so, can we comfortably estimate the isothermal compressibility of a saturated crude-oil with ‘changing liquid oil composition’, below BP pressure?