EOR Feasibility Study of Tanner Oilfield – A Comparative Approach

Alleviating production decline is a challenging task that every oil company will face at some point in the life of an oil reservoir. Enhanced Oil Recovery (EOR) techniques can be implemented to lessen the decline in the oil production rate and improve overall recovery. Despite water injection efforts in the Tanner field, production rate continues to fall, and reservoir pressure conditions have declined, making conventional primary and secondary recovery economically non-viable. This study evaluates the feasibility of Enhanced Oil Recovery (EOR) methods for a mature Tanner field. Four injection techniques—Continuous CO2 Injection, Water Alternating Gas (WAG), Carbonated Water Injection (CWI), and Alkaline Surfactant Polymer (ASP) were simulated in the reservoir model. The ECLIPSE simulator was employed to model EOR techniques on the reservoir from May 2000 to January 2021. Simulation results indicate that, Carbonated Water Injection with an injection pressure of 2000 psia returned the highest recovery factor of 28% OIIP and total oil production of 1.28MMstb. The highest FOE was observed during Carbonated Water Injection. The economic analysis of future performance revealed that CWI achieved the highest Net Present Value (NPV). Carbonated Water Injection (CWI) is considered the optimal EOR technique for the tanner field as it yields a higher NPV and the highest recovery factor. The novelty of this study lies in its evaluation of the feasibility of various EOR techniques, considering both technical and economic aspects. The findings hold significant implications for optimizing EOR strategies in mature fields.