A short review of biopolymers for enhanced of oil recovery in mature fields

Abstract

The enhanced oil recovery (EOR) techniques are employed to recover more oil from mature reservoirs following the primary and secondary stages of oil production. Polymer flooding is a chemical EOR method that involves the addition of polymer molecules to a treated area to improve its water viscosity and sweep efficiency, and to accelerate oil production. The increased water viscosity will reduce the mobility ratio of the injected fluid to the reservoir fluid. Polymer flooding is most effective when applied in the early stages of a water flood while the mobile oil saturation is still high. The polymers used in polymer flooding are divided into synthetic polymers and biopolymers. Unfortunately, synthetic polymers are susceptible to brine formation and high temperatures. On the other hand, biopolymers have a more rigid chemical chain structure making them more resistant to high temperatures (about 135°C) and salinity (about 220 g/L). This review presents a comprehensive discussion of the use of polymers for EOR applications. First, a summary and explanation are given of the structure and characterization of polymers. Subsequently, the general screening criteria for polymer flooding are highlighted. Then, the properties of synthetic and natural polymers and their application in EOR are presented. Finally, the limitations of this study and suggestion for future work on polymers in EOR are explained.