Using Hydraulic Barrier Control CO2 Plume Migration in Sloping Reservoir

Zhao Ruirui; Cheng Jianmei

doi:10.3799/dqkx.2016.056

Abstract：CO 2 will rapidly migrate toward the up-tilt direction of the formation under buoyancy when CO 2 is stored in the slop-ing aquifers.This phenomenon is not conducive to the storage security.In this paper,we are proposed setting water injection wells at a certain distance from the CO 2 injection well in the up-tilt direction of the formation.Then hydraulic barrier is created to retard upward CO 2 migration.The numerical model is set up to investigate the effectiveness of this approach,and to analyze the effects of some factors,for instance,the injection position,the injection distance and the injection rate.The results show that the hydraulic barrier caused by injecting water can effectively retard upward CO 2 migration and enhance CO 2 dissolution. Pumping water can significantly reduce the formation pressure.To ensure that CO 2 is completely retarded,the length of the in-jection water needs to be greater than the thickness of the CO 2 plume,even injecting water through all thickness of the forma-tion.The rate of the injection water is the key factor affecting the effectiveness of the hydraulic barrier.The effectiveness is bet-ter when the injection water well is closer to the CO 2 injection well.The water can be injected just before the arrival of CO 2 plume to reduce the amount of injected water and energy consumption.