Review on chemical enhanced oil recovery using polymer flooding: Fundamentals, experimental and numerical simulation

TLDR

EOR techniques, including polymer flooding, are used to recover additional oil from mature reservoirs by increasing water viscosity to improve mobility ratios and sweep efficiencies, especially when applied early and as a key component in alkaline‑polymer or alkaline‑surfactant‑polymer processes. The study aims to review the fundamentals of polymer flooding and its synergy with surfactant and alkaline methods in chemical enhanced oil recovery. The review examines experimental and numerical simulation aspects of polymer flooding, addressing challenges in high‑temperature, high‑salinity environments and exploring its combination with surfactant and alkaline agents. Polymer flooding improves vertical and areal sweep efficiencies relative to conventional water flooding.

Abstract

The EOR techniques are employed to recover more oil from mature reservoirs after the primary and secondary oil production stages. Polymer flooding as a chemical EOR method involves adding polymer molecules in order to increase water viscosity. Increasing water viscosity will improve the mobility ratio of injected fluid to reservoir fluid toward a more favorable value. Therefore, vertical and areal sweep efficiencies are increased compared to typical water flooding. Polymer flooding will be most effective if applied in the early stages of a water flood while the mobile oil saturation is still high. Polymer is also a critical component when considering other chemical EOR technologies such as alkaline-polymer or alkaline-surfactant-polymer. The present study covers two main parts. In the first part, fundamental of polymer flooding as it related to experimental work and simulation are discussed. The challenge of polymer flooding applications in high temperature and high salinity (HTHS) environment is also discussed in this part. In the second part, the synergy of polymer with surfactant and alkaline as chemical enhancing oil recovery (CEOR) methods is discussed.