Indexed by:会议论文

Date of Publication:2014-08-10

Included Journals:EI

Abstract:The method of injecting CO2into depleted or low permeability reservoirs is an effective way for enhanced oil recovery and geological CO2storage. Mass transfer is the first mechanism to occur when CO2is injected into the reservoirs. In order to effectively evaluate CO2flooding efficiency and underground storage safety, it's necessary to study the process of CO2diffusion and mass transfer in the oil. In this study, the dualchamber pressure decay method and magnetic resonance imaging (MRI) were used to dynamically visualize the CO2diffusion process in oil-saturated porous media, and the relations of concentration-distance for CO2diffusing into oil at different times for CO2-oil system were obtained by quantitative analysis. A non-iterative finite volume method was successfully applied to calculate the diffusion coefficient of CO2in oil-saturated porous media. The results agree very well with the conventional pressure decay method in binary mixtures. According to the experimental and calculating results, it is found that the CO2concentration gradually declines along the diffusion direction, and the CO2concentration at later times are higher than the CO2concentration at early time during the process of CO2diffusion in oil-saturated porous media.