Analyzing the microbial factors affecting microbial enhanced oil recovery through numerical simulation study

Abstract

ABSTRACT Primary and secondary recovery methods are usually not sufficient to maximize the oil recovery. In many cases, more than 40% of the Oil Initially in Place is left in the reservoir after implementing these recovery methods. To resolve the issue at hand, petroleum engineers have at their disposition a plethora of tertiary recovery methods such as chemical flooding, thermal recovery, and microbial enhanced oil recovery (MEOR). In this study, we propose the use of MEOR: a technique that uses naturally occurring microbes in the reservoir or injected microbes to enhance the oil recovery. The MEOR process is governed by several mechanisms such as viscosity reduction, relative permeability alteration, capillary pressure alteration, and other reaction-induced system changes such as pressurization. This study investigates the impact of these mechanisms on the hydrocarbon production by conducting a numerical simulation using our in-house MEOR numerical simulator. In the base case study, the case with MEOR shows the 20% of oil production improvement than the case without MEOR. We conduct a sensitivity analysis to evaluate the impact of microbial factors affecting MEOR to the system responses and production behavior, where the maximum growth rate of microbes is found to be the most influential factor with the scaled sensitivity coefficient of 1.384 × 105. The findings provide the relative impacts of factors affecting the performance of MEOR, which subsequently suggest the factors to be investigated with emphasis for oil production improvement in the MEOR applications.