Innovative EOR Modelling Confirmed Substantial Production Gains Following Improved Recovery Through Seawater Injection in a Giant, Mature Oil Field in the Gulf of Suez

Abstract This paper presents a novel approach by integrating polymer with low-salt water injection for the first time in an Offshore Giant Field in Gulf of Suez, Egypt, harnessing two synergistic mechanisms for Enhanced Oil Recovery (EOR). Specifically, designed low-salt water reduces Sor by around 3 units as proven from lab experiments, while the addition of specially designed polymer improves the mobility ratio for more efficient displacement. This innovative technique holds significant potential in improving and pushing the field's ultimate recovery factor to the top limit. This case study outlines the methodology and outcomes of investigating those EOR techniques, which incorporates tailored low-salt water injection with polymer injection to maximize oil recovery. This strategy was tested after decades of seawater injection-based oil recovery improvements. The oil field of interest, which is one of the largest in Egypt's Gulf of Suez with a stock-tank original oil-in-place (STOIP) exceeding 2 billion STB and more than 300 wells and sidetracks, has been producing since 1965. Seawater injection was introduced in 1970 due to weak aquifer support. Despite achieving more than 50% recovery factor, the oil field of interest still has potential to be tapped. Seawater injection for decades has already proven its impact on initial residual oil saturation (Sor) reduction as observed from core data and initial logs. Before the launch of a full pilot EOR project, a detailed simulation sector model, incorporating this innovative EOR method, was developed to evaluate the field potential, estimate the incremental volumes to be recovered, and optimize the type of polymer used