关键词: 热自生CO2 吞吐技术, 稠油, 蒸汽吞吐, 降黏率, 提高采收率

Abstract:

Hot self-generated CO2 technology is focused on the problems of recovery difficulty，poor effect of steam soaking
and so on for heavy oil reservoirs. This technology combines steam flooding and gas flooding and improves the effect of steam
soaking in heavy oil reservoir. Its main mechanism is the application of steam to heat blowing agent and generate a large volume
of gases（including CO2，NH3，etc）in the formation. Some of these gases react with the oil to reduce the oil viscosity，others
form miscible flooding to reduce water interfacial tension，so as to enhance oil recovery. An optimized selection of the heat
blowing agents was performed. By comparing the difference of blowing agent solution before and after the reaction，we find
that alkaline increases after the reaction（pH changes in value from 8.26 to 9.71~10.02），which is helpful to reduce oil viscosity
and lower interfacial tension，etc. Studies indicate that Heat-generating CO2 flooding technology can get a maximum viscosity
reduction rate of 76.7%；oil-water interfacial tension decreases by 54.77%，and further improve oil recovery by 4.18% in the
5th steam soaking. Single cycle input-output ratio averages 1.0：3.2，which shows a technical advantage toward conventional
EOR method and a preferable economic profit. The field experiments found that the technique can greatly improve the oil
production，which will provide a powerful technical supporting for the efficient development of heavy oil.

Key words: hot self-generated CO2 technology, heavy oil, steam soaking, viscosity reduction rate, EOR