Systematic modelling incorporating temperature, pressure, and salinity effects on in-situ microbial selective plugging for enhanced oil recovery in a multi-layered system

Abstract

The microbial enhanced oil recovery (MEOR) process has been identified as a promising alternative to conventional enhanced oil recovery methods because it is eco-friendly and economically advantageous. Despite its various advantages, the technique is not widely applied because the reservoir conditions such as temperature, pressure, and salinity are extremely harsh for microbial survival. In this study, an accurate microbiological model incorporating the environmental effects has been developed. The efficiency of the MEOR process based on selective plugging by microbial biopolymer generation has been examined in multi-layered systems with high permeability contrast. The MEOR is applied to multi-layered reservoirs of different environmental conditions. When the MEOR is applied to a high temperature reservoir, there is an optimum injection temperature that can greatly improve the oil production. Oil productivity in a high-pressure reservoir is estimated to decrease by 15% when the pressure effect is considered. We simulated different salinity conditions and showed that oil recovery decreased with increasing salinity and only was affected by injected water salinity. The oil recovery obtained by the developed model included all three environmental effects and provided estimates 21% lower than that of a previous model that did not account for the environmental effects.