Oil in place for undersaturated oil reservoirs without fluid injection
Input(s)
\(\mathrm{N}_{\mathrm{p}}\): Produced Oil (STB)
\(B_{\mathrm{o}}\): Oil Formation Volume Factor (rb/STB)
\(\mathrm{B}_{\mathrm{oi}}\): Initial Oil Formation Volume Factor (rb/STB)
\(\mathrm{S}_{\mathrm{wi}}\): Initial Water Saturation (fraction)
\(\mathrm{c}_{\mathrm{w}}\): Water Compressibility (1/psi)
\(\mathrm{c}_{\mathrm{f}}\): Formation Compressibility \((1 / \mathrm{psi})\)
\(\Delta \mathrm{P}\): Pressure Differential (psi)
Output(s)
\(\mathrm{N}\): Oil in Place \((\mathrm{STB})\)
Formula(s)
\[
\mathrm{N}=\frac{\mathrm{N}_{\mathrm{p}} * \mathrm{~B}_{\mathrm{o}}}{\mathrm{B}_{\mathrm{o}}-\mathrm{B}_{\mathrm{oi}}+\mathrm{B}_{\mathrm{oi}} *\left(\frac{\mathrm{S}_{\mathrm{wi}} * \mathrm{c}_{\mathrm{w}}+\mathrm{c}_{\mathrm{f}}}{1-\mathrm{S}_{\mathrm{wi}}}\right) * \Delta \mathrm{P}}
\]
Reference(s)
Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 5, Page: 333 .