Optimization of CO2 Flooding Injection Parameters in Low Permeability Reservoirs
摘要
In view of the low oil production rate and low recovery degree in water flood development of low permeability reservoirs, the CO2 flooding laboratory experiments are carried out. The experimental results show that the volume expansion and viscosity reduction of crude oil are obvious in the process of CO2 flooding in low permeability reservoirs, which is conducive to improving oil recovery ratio. The minimum miscible pressure of the target reservoir is 30.76 MPa, which is lower than the current formation pressure of 34.0 MPa. Therefore, the CO2 miscible flooding can be achieved under the current formation pressure. According to the optimization results of CO2 flooding injection parameters, the CO2 injection concentration is more than 90%, the optimal CO2 injection volume is 0.4 PV, and the optimal water–gas ratio is 1:1.