摘要：The effect of CO 2 adsorption on oil displacement in tight reservoirs is analyzed. The composition of clay minerals in a reservoir is analyzed, and a molecular model of the formed rock structure is established to investigate the adsorption characteristics of different clay minerals on the fluid. The effect of CO 2 adsorption on oil displacement is investigated through a CO 2 injection experiment. The results show that the adsorption capacity of reservoir minerals is greater for light hydrocarbons than for heavy hydrocarbons as well as for water and CO 2 than for hydrocarbons, indicating that the oil recovery rate of the reservoir composed primarily of silica is higher when supercritical CO 2 and water are alternately injected. The oil recovery can reach 23.78% by water and CO 2 alternate flooding. Intermittent stop injection enable CO 2 to enter rock samples more easily, and crude oil can subsequently be discharged more easily. As the mixing of CO 2 and crude oil cannot be realized under the experimental conditions, the intermittent stop injection time is short and the gravity migration in tight cores is slow. Hence, we infer that the adsorption of CO 2 significantly affects the displacement of tight reservoirs.
关键词：Adsorption ; Tight oil ; Supercritical carbon dioxide ; Water gas alternative flooding ; Molecular dynamics ; Gas channeling
