Combined Polymer-Surfactant Flooding and Low Salinity Water for Enhanced Oil Recovery in Dolomite Reservoirs using Local and Synthetic Polymers

In last years, there has been a growing
interest in the effect of reducing salinity of injected water
in oil recovery. Numerous studies have demonstrated
that low salinity waterflooding is a promising method
that can lead to a significant reduction in residual oil
saturation compared to traditional water flooding. The
mechanisms behind improved oil recovery by low
salinity water flooding are not fully understood, but
many researchers have claimed wettability alteration.
Investigation has been carried out to characterize the
polymers and surfactant solutions in terms of their
ability to improve oil recovery in their aqueous solutions.
A series of flooding experiments have been conducted to
find the additional recovery using polymer and
surfactant slug. In this research, the effect of low salinity
water flooding on improving oil recovery is investigated
in six Dolomite cores. In addition a combined low
salinity and polymer-surfactantslugs injection were
conducted in tertiary mode to determine and optimize its
effectiveness in increasing oil production. The tertiary
low salinity surfactant-polymer slugs injection showed
an increase in oil recovery with increasing size of
surfactant slug injected at constant surfactant
concentration. The wettability of the cores had impact on
the efficiency of the slugs injected on oil recovery.