See also

\rm RF = \frac{Q_{OIL}}{V_{STOIIP}} = E_D \, E_S = E_D \, E_{SV} \, E_{SH}

\rm WIR = \frac{Q_{OIL}}{Q_{INJ}}

\rm ROI_{WF} = \frac{Cashin_{Q_{OIL}}}{Cashout_{Q_{INJ}}} = WIR \cdot \frac{Cashin[
\text{1 bbl oil]}}{Cashout[\text{1 bbl water injection}]}