Experimental and numerical simulation of the recovery of oil and the effect of light oil components on CO2 flooding mechanism using sandstone reservoir.

Abstract

Carbon dioxide (CO2) flooding is considered as an efficacious method of EOR. It is a complicated process as it involves phase behavior. In order to master the performance of CO2 flooding, a comprehensive investigation of mass transfer mechanism and compositional changes for gaining miscibility based on laboratory study was conducted. In this manuscript, CO2flooding experiments were carried out on Bentheimer Sandstone and Berea Sandstones under three temperature conditions (50°C, 70°C and 90°C). During the flooding, fluid samples were analyzed to elucidate the effect of light components on the recovery of model oils (Live-oil A and Live-oil B) and crude oil from a field in the North Sea. Model oils were prepared using different composition of light components (C1 and C3) combined with n-decane.CO2flooding experiments were also performed with CO2containing light components (C1 and C3) to comprehend the effect of light oil components on the recovery when present in the displacing fluid and displaced fluid. The experimental and simulation results have highlighted that higher miscible condition provides higher recoveries. Light components also affect the recovery of the oil. The recoveries obtained with the oil consisting of only methane as a light component provided higher recovery than the oil consisting of both methane and propane. However, the incremental recovery was observed when the light components were displacing fluid with CO2. This may be due to that the presence of light components in the injected fluid in a miscible condition increased the oil mobility. This dissertation addressed material balance of all the studied components and compared the experimental result with the simulated one.