Numerical study of immiscible CO2 flooding in thick reservoirs with positive rhythm

Benefitting from the development of carbon capture and storage (CCS) technology, CO2 flooding for enhanced oil recovery (EOR) has become increasingly attractive to the petroleum industry. This paper presents a numerical study about the feasibility and efficiency of the immiscible CO2 flooding process, which is a potential tertiary oil recovery method for use after water flooding, with advantages of lower cost and fewer facility requirements than miscible CO2 flooding. A numerical simulation model established from laboratory experimental results was used to predict fluid behaviour and influence factors of immiscible CO2 flooding in thick reservoirs with positive rhythm to enhance oil recovery after water flooding. Injection and confining pressure conditions are both important to the displacement process and results.