QUICK ASSESSMENT OF CO₂-EOR AND CO₂ SEQUESTRATION POTENTIAL IN HUIZHOU21-1 OILFIELD, PEARL RIVER MOUTH BASIN,

Guangdong Province is one of the biggest CO₂ emitters in China. Large CO₂ emission sites are mainly distributed along the coast, close to the potential offshore geologic storage sites in the Pearl River Mouth Basin (PRMB). Therefore, it is important for low-carbon economic development in Guangdong Province to assess the potential and feasibility of offshore CO₂-Enhanced Oil Recovery (EOR) and carbon storage. Using a quickly screening model for CO₂ flooding and storage, the potential of CO₂-EOR and storage in Huizhou (HZ) 21-1 oilfield are assessed in this study. The aim is to quickly evaluate CO₂-EOR and CO₂ storage candidates in 6 oil reservoirs of the HZ21-1 oilfield. The quick-look assessments indicate that: (1) M10, L60 and L40Up would be the more promising reservoirs with higher dimensionless recovery factor (51%, 51% and 40% respectively) and shorter breakthrough time than others such as L50, L30 and L40Low; All of these six reservoirs would approximately store 0.8PV (Pore Volume) of CO₂; Comprehensively considering the Original Oil In Place (OOIP) and reservoir properties of those more promising reservoirs, M10 would be the most suitable site for CO₂-EOR and CO2storage; (2) In sensitivity analysis, all factors except minimum miscible pressure would have an linear impact on reservoir behavior, and initial oil saturation at the beginning of CO₂ injection and injection pressure would significantly affect oil recovery, while CO₂ injection pressure would affect breakthrough time and potential on dimensionless CO₂ storage. CO₂ storage capacity is more sensitive than breakthrough time regarding injection pressure. Hence in general, while initial oil saturation and minimum miscible pressure are constant, higher CO2injection pressure may increase EOR and carbon storage efficiency.