A review on polymer flooding in enhanced oil recovery under harsh conditions
Polymer flooding is a commercially verified technology to enhance the recovery of residual oil from oil reservoirs. Polymers are used to increase the viscosity of the displacing phase. Accordingly, they resulted in a significant reduction in the mobility ratio between the water and oil. Due to the decrease in the mobility ratio, the sweep efficiency will significantly increase compared to water flooding. This paper aims to provide a comprehensive review on thermal and chemical stability and the rheological properties of various water soluble polymers used in sandstone and carbonate reservoirs. The properties of conventional and novel water soluble polymers applied in enhanced oil recovery (EOR) are discussed along with their limitations. Moreover, field and laboratory core flooding data of different water soluble polymers are presented. This review covers current research studies on the application of polymer flooding to high temperature and high salinity reservoirs. It also provides recommendations for future work on synthesis of novel polymers with higher stability under harsh reservoir conditions.