# Hydrocarbon pore volume occupied by gas cap

## Input(s)

m: Ratio of Initial Gas Cap Gas Reservoir Volume to Initial Reservoir Volume (bbl/bbl)

\(\mathrm{N}\): Initial Oil in Place (STB)

\(\mathrm{B}_{\mathrm{oi}}\): Initial Oil Formation Volume Factor (bbl/STB)

\(\mathrm{B}_{\mathrm{gi}}\): Initial Gas Formation Volume Factor \((\mathrm{bbl} / \mathrm{SCF})\)

\(\mathrm{B}_{\mathrm{g}}\): Current Gas Formation Volume Factor \((\mathrm{bbl} / \mathrm{SCF})\)

## Output(s)

V: Volume of the Gas Cap at Current Pressure (bbl)

## Formula(s)

\[
\mathrm{V}=\frac{\mathrm{m} * \mathrm{~N} * \mathrm{~B}_{\mathrm{oi}} * \mathrm{~B}_{\mathrm{g}}}{\mathrm{B}_{\mathrm{gi}}}
\]

## Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 4, Page: 301 .