중질유 저류층에서 마이크로 젤 처리기법과 WAG 기반의 하이브리드 EOR 공법 모델링

Abstract

Studies on CO2 injection in heavy oil fields have been widely performed to reduce the viscosity of oil and to make oil swell in recent decades. However, unfavorable mobility ratio between oil and CO2 is considered as a serious obstacle. To overcome this, a hybrid EOR process, which combines gel treatment and CO2 WAG flooding, has been proposed as one of potential remedies. In order to demonstrate its effectiveness in heavy oil reservoir, it was compared with other processes including waterflooding, WAG flooding, and gel treated waterflooding. Concentration-dependent flowing gel viscosity system was included to describe the behavior of microgel more accurately. According to results, microgel-assisted WAG improved recovery factor about 24%p with reducing GOR by 50% and 158 days earlier WOR reduction time compared to WAG process. For WAG considering flowing gel viscosity, GOR decreased about 83% and WOR decreasing time advanced by 365 days in comparison with WAG, and oil recovery factor was improved by 31%p. Enhanced oil recovery factor improved by considering flowing gel viscosity was estimated to be 7%p.