Study On Injection And Production Parameters Of CO₂ Combined Steam Flooding In Steam Flooding

The technology of mining heavy oil by steam is a method of wide range of use and producing more oil.Among them.Gravity overshoot is due to the large difference in density of steam and crude oil,which causes the steam to cross the oil zone.Viscosity refers to the difference between the viscosity of the steam and the viscosity of the crude oil,bypassing the oil band.Due to the existence of such problems,low recovery rate,high moisture content and low oil-steam ratio are obtained in the late stage of steam flooding.The Karamay Oilfield in Xinjiang proposed an implementation plan for steam flooding CO2 steam flooding at later stages to improve steam flooding.In this paper,a lot of literature researches have been conducted on the study of CO2 composite steam flooding at home and abroad.On this basis,we first learned about the geology of the Karamay oilfield in Xinjiang and analyzed the development status of the Qigu Formation firstly;Then use OFM software to do a dynamic analysis of the injection and production data in the 9th district,and analyze the reasons for the high moisture content,low oil-steam ratio,and low recovery factor in the later stage of steam drive in the 9th district;Finally,a“dual mode”study was conducted and a development model for CO₂ flooding that promotes expansion of the steam chamber and gravity drainage in vertical wells was proposed.The three key factors affecting the CO₂ flooding were identified:steam quality,perforation adjustment and solidification.Well quality,Using CMG's STARS software to historically fit the injection and production data of the 9th district,studied the optimization design of the key implementation parameters,completed the CO₂ composite steam flooding implementation program,and optimized the implementation parameters.