Oil in place in saturated oil reservoirs

Input(s)

$\mathrm{N}_{\mathrm{p}}$: Cumulative Oil Production (STB)

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

$\mathrm{G}_{\mathrm{p}}$: Cumulative Gas Production (MSCF)

$\mathrm{R}_{\mathrm{s}}$: Gas Solubility $(\mathrm{SCF} / \mathrm{STB})$

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

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

$\mathrm{R}_{\mathrm{si}}$: Initial Gas Solubility $(\mathrm{SCF} / \mathrm{STB})$

Output(s)

$\mathrm{N}$: Oil in Place (bbl)

Formula(s)

$$ \mathrm{N}=\frac{\mathrm{N}_{\mathrm{p}} * \mathrm{~B}_{\mathrm{o}}+\left(\mathrm{G}_{\mathrm{p}}-\mathrm{N}_{\mathrm{p}} * \mathrm{R}_{\mathrm{s}}\right) * \mathrm{~B}_{\mathrm{g}}}{\mathrm{B}_{\mathrm{o}}-\mathrm{B}_{\mathrm{oi}}+\left(\mathrm{R}_{\mathrm{si}}-\mathrm{R}_{\mathrm{s}}\right) * \mathrm{~B}_{\mathrm{g}}} $$

Reference(s)

Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 5, Page: 334 .