During CO_(2) injection in deep saline aquifers, salt precipitation happens around the injection well because of capillary driven back flow, inducing permeability impairment. The permeability impairment affects CO_(2)...During CO_(2) injection in deep saline aquifers, salt precipitation happens around the injection well because of capillary driven back flow, inducing permeability impairment. The permeability impairment affects CO_(2) injectivity and migration. Different values of three characteristic parameters for capillary pressure function (air entry pressure, empirical parameter m and liquid residual saturation) as well as input absolute value of maximum capillary are chosen in numerical simulation to figure out their effects on salt precipitation. Verma & Pruess model is then used for quantifying permeability impairment. Results show that permeability decreases with higher air entry pressure, larger liquid residual saturation, and especially smaller value of empirical parameter m. To enhance CO_(2) injectivity and avoid blocking of CO_(2) migration, a homogenous formation with large pore size should be chosen before CO_(2) injection into deep saline aquifer.展开更多
基金Foundation item:Project(51179060)supported by the National Natural Science Foundation of ChinaProject(20110094130002)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘During CO_(2) injection in deep saline aquifers, salt precipitation happens around the injection well because of capillary driven back flow, inducing permeability impairment. The permeability impairment affects CO_(2) injectivity and migration. Different values of three characteristic parameters for capillary pressure function (air entry pressure, empirical parameter m and liquid residual saturation) as well as input absolute value of maximum capillary are chosen in numerical simulation to figure out their effects on salt precipitation. Verma & Pruess model is then used for quantifying permeability impairment. Results show that permeability decreases with higher air entry pressure, larger liquid residual saturation, and especially smaller value of empirical parameter m. To enhance CO_(2) injectivity and avoid blocking of CO_(2) migration, a homogenous formation with large pore size should be chosen before CO_(2) injection into deep saline aquifer.
