Evaluation of CO2 storage capacity and injectivity using a relief well in a saline aquifer in Pohang basin, offshore South Korea

This study presents the numerical results of CO2 injectivity for CO2 sequestration in a saline aquifer in Pohang basin, offshore southeast Korea. We analyzed the effect of operating a relief well on enhancement of CO2 storage capacity and injectivity. Geologically, the aquifer boundary is closed along east-south-west, thus the injection of CO2 would yield pressure buildup that limits CO2 storage capacity and injection rate. From the results of simulation, the CO2 storage capacity was calculated as 468 kton in this aquifer, Pohang basin without a relief well. However, when installed a relief well, the capacity was increased to 681 kton which is about 45% larger than the case without a relief well. With the operation of the relief well, the injection rate of CO2 was four times higher than the rate without the relief well from 200 to 800 ton/day in the case of Pohang basin.