Impact of connate water saturation on oil recovery and CO2 storage during secondary carbonated water injection

Nowadays, because of high price of oil and also reaching to the tail end of many oil reservoirs production throughout the world, it is necessary to use Enhanced Oil Recovery (EOR) methods. Among EOR methods, carbonated water injection (CWI) could be an attractive method in Iran because of abundant resources of water and gas. In this method, water and CO2 (carbon dioxide) are used when they are soluble in each other as a single phase. This method can alleviate the shortcomings of direct injection of water and gas at pore level. Injection process of CW has higher oil recovery efficiency and also from environmental prospect, it can be applied to store CO2 in underground. In this method, water can play as a barrier between oil and gas phases. Hence water content can adversely affect both oil recovery and CO2 storage capacity in CWI process. In this paper, the results of different connate water saturations (Swc) effects on ultimate oil recovery and CO2 storage capacity during secondary CWI (SCWI) are presented. This study has been carried out on rock samples from outcrop of an Iranian carbonate oil reservoir. The results indicate higher ultimate oil recovery and CO2 storage at the experiments with lower connate water saturation.

Impact of connate water saturation on oil recovery and CO2 storage during secondary carbonated water injection Keywords:

Carbonated water , connate water , Iranian carbonate reservoir , enhanced oil recovery , CO2 storage