Application of CO2 miscible flooding in ultra-low permeability beach-bar sand reservoir

The beach-bar sand reservoir of the Sha 4 Member Shahejie Formation in Dongying Sag is main oil-bearing formation this area. In recent years, its proven reserves have been getting lower and lower, poor petrophysical properties made water injection development difficult. turn, it results a rapid decline elastic productivity low oil recovery. study, experimental evaluation numerical simulation research on adaptability CO 2 flooding reservoirs are carried out basis fully investigating successful examples conducted by previous. According to geological characteristics CL area Sag, reasonable engineering parameters surface procedures for formulated. Experiments show that after completion flooding, recovery factor continuous 85.64%. It proves higher than flooding. Field tests shown molecules behave supercritical state underground, which easier being injected into water. addition, displacement distance obviously larger development. gas-oil ratio variation different types different, can effectively increase energy, improve economic benefits type reservoir.