Water-drive index for gas reservoirs
Input(s)
\(\mathrm{W}_{\mathrm{e}}\): Cumulative Water Influx (bbl)
\(\mathrm{W}_{\mathrm{p}}\): Cumulative Water Production \((\mathrm{bbl})\)
\(\mathrm{B}_{\mathrm{w}}\): Water Formation Volume Factor (rb/STB)
\(\mathrm{G}_{\mathrm{p}}\): Cumulative Gas Production at Depletion Pressure (MSCF)
\(\mathrm{B}_{\mathrm{g}}\): Gas Formation Volume Factor at Depletion Pressure (bbl/SCF)
Output(s)
WDI: Water Drive Index (dimensionless)
Formula(s)
\[
\mathrm{WDI}=\frac{\mathrm{W}_{\mathrm{e}}-\mathrm{W}_{\mathrm{p}} * \mathrm{~B}_{\mathrm{w}}}{\mathrm{G}_{\mathrm{p}} * \mathrm{~B}_{\mathrm{g}}}
\]
Reference(s)
Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 211.