* ''E''<sub>P</sub> = pattern efficiency or pattern swept by total pattern area
* ''E''<sub>P</sub> = pattern efficiency or pattern swept by total pattern area
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The displacement efficiency is a function of residual oil saturation (''S''<sub>or</sub>) of the swept region. The following equation gives the displacement efficiency as a function of ''S''<sub>or</sub> and the interstitial (irreducible) water saturation (''S''<sub>wi</sub>):
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The displacement efficiency is a function of residual oil saturation (''S''<sub>or</sub>) of the swept region. The following equation gives the displacement efficiency as a function of ''S''<sub>or</sub> and the [http://petrowiki.org/Glossary%3AIrreducible_water_saturation interstitial (irreducible) water saturation] (''S''<sub>wi</sub>):