Potential evaluation of CO2 EOR and sequestration in Yanchang oilfield

CO2 storage in oil reservoirs is not only an effective method for reducing CO2 emissions and greenhouse effect, but also a superior choice by enhancing oil recovery economically. This option, which lowers CO2 sequestration cost by recovering incremental oil, is particularly attractive in mature oil fields, such as Yanchang oilfield in China where many oil pools are near depletion and where most of the needed infrastructure is already in place. Using screening criterion, MMP determination and capacity evaluation methods, the feasibility of CO2 flooding, potential CO2 EOR and CO2 storage capacity of twenty-seven reservoirs in Yanchang Oilfield were evaluated. Results show that of all the 27 reservoirs only 8 are suitable for implementing CO2 EOR and sequestration project with average CO2 storage coefficient of 0.185, demonstrated the CO2.sequestration potential in Yanchang oilfield is very limited.