Injection mode of CO2 displacement in heavy oil reservoirs

CO2 injection has been an important enhanced oil recovery method adopted at the later stage of oilfield development, and a series of studies and field experiments has been done in recent years. However, there are some problems in this process, such as viscous fingering, gravity override, channeling of CO2 in heterogeneous reservoir. These challenging issues are closely related to the CO2 injection ways. At present, it is at development stage and calls for more research on optimally choosing CO2 injection methods to displace oil. This research mainly uses different CO2 injection methods to displace oil, in order to optimally choose the CO2 injection method that fit this experiment area, and does research on the effects and principles of CO2 drive to enhance oil recovery. Compared with gas flooding and WAG, CO2 foam greatly reduce the mobility of the injected gas and expand the sweep volume. This is consistently observed in the numerically simulated foam process at the field level.