Potential evaluation of CO2 EOR and storage in oilfields of the Pearl River Mouth Basin, northern South China Sea.

Abstract: The Pearl River Mouth Basin (PRMB) is the largest petroliferous sedimentary basin in the northern South China Sea. It is near the coastal economic zone of Guangdong province where a large number of CO₂ emission sources are located. Carbon dioxide enhanced oil recovery (EOR) represents an opportunity to promote offshore carbon capture, utilization and storage (CCUS) deployment because CO₂ flooding offers a method to recover additional oil while simultaneously sequestering anthropogenic CO₂. In this paper, a comprehensive multiparameter ‘quick look’ and potential evaluation method was proposed to screen and assess offshore CO₂ EOR potential. A screening scheme for the CO₂ EOR potential of reservoirs of the PRMB was also proposed using additional parameters, including reservoir properties and engineering design incorporating a dimensionless screen model and calculations. The results show that the suitability of reservoirs for CO₂ EOR and storage varies and could be categorized into four priority grades. Approximately 30 of the oil reservoirs from 10 oilfields were preferentially identified by applying the screening method for reservoirs with predicted higher ultimate recovery potentials. It was predicted that 3227 × 10⁴ t of additional oil could be produced from these reservoirs and that 3617 × 10⁴ t of CO₂ could be simultaneously stored. The sensitivity analysis shows that injection pressure (P_inj) would be more sensitive than production pressure (P_p) and well distance (L) on the CO₂ EOR and storage efficiency, indicating that EOR operations with higher P_inj may improve oil production. The prospective reservoirs include those candidates with suitability grades of I and II from the Lufeng (LF) and Huizhou (HZ) oilfield clusters, where 1164 × 10⁴ t of additional oil could be produced and 1464 × 10⁴ t of CO₂ stored with CO₂ EOR. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]