Trapped gas volume in water-invaded zones
Input(s)
\(\mathrm{W}_{\mathrm{e}}\): Cumulative Water Influx (bbl)
\(\mathrm{W}_{\mathrm{p}}\): Cumulative Water Produced (bbl)
\(\mathrm{B}_{\mathrm{w}}\): Water Formation Volume Factor (bbl/STB)
\(\mathrm{s}_{\mathrm{wi}}\): Initial Water Saturation (fraction)
\(\mathrm{s}_{\text {grw }}\): Relative Gas Saturation (fraction)
Output(s)
TG: Trapped Gas Volume (MSCF)
Formula(s)
\[
\mathrm{TG}=\left(\frac{\mathrm{W}_{\mathrm{e}}-\mathrm{W}_{\mathrm{p}} * \mathrm{~B}_{\mathrm{w}}}{1-\mathrm{s}_{\mathrm{wi}}-\mathrm{s}_{\mathrm{grw}}}\right) * \mathrm{~s}_{\mathrm{grw}}
\]
Reference(s)
Ahmed, T., McKinney, P.D.2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 208 .