Techno-economic evaluation of CO₂enhanced oil recovery (EOR) with the optimization of CO₂ supply

Abstract

Enhanced oil recovery (EOR) by the injection of CO2 into the oil reservoir is widely practiced for stimulating oil production, which is also favorable for CCS (carbon capture and storage) due to the effect of sequestrating CO2 into the empty space of the reservoir along with oil production. Although economic and environmental benefits can be obtained through CO2 EOR, it requires considerable capital investment and expenditure for the operation. Therefore, it is helpful to assess systematically the life-time effect of CO2 EOR by evaluating the capital and energy flow. Rather considering collectively overall mass flows of CO2 purchase, recycling, sequestration and oil production throughout the whole life-cycle, this study presents the assessment of CO2 EOR in a multi period manner in which CO2 supply is systematically scheduled, subject to the availability of external CO2 sources and time-dependent relationship between CO2 injection, CO2 supply and CO2 recycle. The methodological procedure for the proposed economical assessment is presented with the case study, in which CO2 supply schedule is optimized to maximize net present value (NPV), considering the constraints imposed by time-dependent availability of CO2 supply sources. Sensitivity analysis of key design parameters is performed to gain conceptual insights for the design and operation of CO2 EOR.