Low salinity oil recovery - an experimental investigation

TLDR

Injecting low‑salinity water into reservoirs has been practiced since the 1970s and various mechanisms for its enhanced oil recovery have been proposed. The study experimentally investigates factors controlling the enhanced oil recovery seen when low‑salinity brine is injected into oil‑saturated core samples. The authors performed extensive chemical analyses of the effluent to assess interactions among injected brine, oil, and rock matrix. The results confirm that injecting sufficiently low‑salinity water improves oil recovery.

Abstract

The idea of injecting low salinity water into a petroleum reservoir is not novel and was often used in the 70s prior to the injection of surfactant. Recently it was shown that simply injecting sufficiently low salinity water improves oil recovery. Many possible mechanisms concerning low-salinity waterflood have been proposed in the literature. This paper describes an experimental investigation into some of the factors controlling the increased oil recovery observed when low salinity brine is injected into oil saturated reservoir core samples. Extensive chemical analyses were performed on the effluent showing the extent of interaction between the injected brine, the oil and the rock matrix.