Experimental Study Of CO₂ Assisted Steam Stimulation In Heavy Oil

It is very difficult to exploit the heavy oil reservoir for its higher viscosity,and less effective by steam stimulation method. In order to enhance the recovery of super-heavy oil reservoirs, the method of CO2 assisted steam stimulation is proposed. At the same time,this method can reduce greenhouse gas emissions. Therefore,it can achieve a win-win situation of enhancing oil recovery and environmental protection.This paper analysis the heavy oil reservoir CO2 assisted steam stimulation theoretical systemically, through the iexperiment of oil displacement we studied effect of the exploitation of heavy oil on steam flooding, and carried out the research on injecting the CO2 during the conventional steam drive process.The reslut shows that in the low temperature CO2 can effectively reduce the Gu Dao heavy oil viscosity, with the temperature rise, the temperature became the main factor that inflact the oil viscosity. CO2 can extract C20 and light group the following points in the crude oil. The Cumulative fluid production and inject pressure of steam flooding and common water flooding Changes in the same general trend, while the recovery of steam flooding higher than common water flooding, when the injection speed faster the broken pressure become bigger, the broken time also came later, with the oil recovery improve. Using CO2-assisted steam flooding the oil recovery can thus be enhanced up to almost 40% compared with conventional stream drive, 60% with water drive. And water cut ratet can also be lowered effectively, the water cut rate reduced 6%.