Abstract: With significant potential, the technology of displacing reservoir oil with high-temperature thermal fluids such as waste flue gas from steam injection boiler can not only reduce carbon emission,but also improve oil recovery efficiency.However, the higher outlet temperature and complex composition of flue gas seriously affect the performance of foaming agent,and there are few studies on foaming agent suitable for flue gas displacement.In this connection, a terpolymer foaming agent (PNCAS) for high-temperature flue gas displacement with function of profile control and oil displacement was developed,the performance of foaming agent was studied with high-temperature and high-pressure foam tester,and the effects on foaming performance from foaming agent concentration,temperature, pressure an gas components were also analyzed.The sealing performance was evaluated by using the sand-packed tube displacement experimental device,and the resistance factor of the foaming agent solution was tested,and the dual-pipe parallel displacement and microscopic visualization experiments were conducted.The experimental results proved that PNCAS foaming agent had high resistance and low oil-water interfacial tension after aging at 300 ℃,which significantly reduced the flow rate of flue gas and steam,reduced gas channeling, increased the steam sweeping area, and thus improving the recovery efficiency of heavy oil.The study results play a great guiding role in the heavy oil development with flue gas-assisted thermal recovery.

Key words: flue gas, foam, carbon dioxide, surfactant, heavy oil