Active hydraulic barrier for retarding CO2 migration towards fault during CO2 storage in tilted reservoir

The aquifer which can be used to store CO 2 is likely to be tilted, where CO 2 will move faster towards the upstream direction of the CO 2 injection well under buoyancy force. This feature is not beneficial for the safety of CO 2 storage if there are faults or abandoned wells in the up-tilt side of the CO 2 injection well. In this study, a hydraulic barrier system for retarding CO 2 migration to a fault in a tilted aquifer was proposed and was evaluated by a hypothetical 3D numerical model. In the system, one or three water injection wells are placed at upstream of the CO 2 injection wells to create the hydraulic barrier. In addition, a pumping well is used to decrease the formation pressure. The results indicate that the dip angle of the formation has a great influence on the setting of the injection well. The effectiveness of the hydraulic barrier created by multiple injection wells is better than that of one injection well. In addition, the effectiveness of hydraulic barrier created by active and passive strategies is better than that of hydraulic barrier created by only active strategy. The pumping well should be set between the CO 2 injection well and the fault to effectively decrease the formation pressure.