Experimental investigation of polymer flooding with low‑salinity preconditioning of high temperature–high‑salinity carbonate reservoir

Abstract

Application of polymer flooding in high temperature–high salinity (HTHS) carbonate reservoirs is challenging due to lack of polymers that can withstand such harsh reservoir conditions. The traditional polymers are usually sensitive to high salinity, especially at high temperature. However, injection of low‑salinity make‑up brines may precondition high‑salinity reservoirs before initiating polymer flooding which may reduce chemical degradation of polymer. This study aims to evaluate the effectiveness of a partially hydrolyzed polyacrylamide base polymer for mobility control application in a low‑salinity preconditioned carbonate reservoir and hence on the improvement of oil recovery at HTHS carbonate reservoir. Core flooding experiments using unsteady‑state technique were conducted on reservoir cores with permeability range of 10–100 mD.