Practice of air foam flooding in the Lukeqin deep heavy oil reservoir

The Lukeqin Triassic heavy oil reservoir is recovered via normal-temperature water flooding. However, due to the viscous fingering of injected water, the recovery performance was degraded year by year. To improve the overall development efficiency of the oilfield, the field testing of foam flooding-based EOR of deep heavy oil reservoirs was performed. The high temperature-tolerant high salinity-resistant foaming agent was selected according to the reservoir conditions and the foaming gas and injection parameters were optimized. Then, the field testing of the oxygen-reduced air foam flooding was performed in the YD203 well district in a slug alternating injection pattern. For 19 wells of the YD203 well district, the effective rate for 4 years was 89%, the overall water cut decreased by 39.5%, the cumulative oil production increment exceeded 20000 tons, and the estimated recovery factor of the oilfield was 6.8%. The findings of this research provide important guidance for further improving the recovery factor of the Lukeqin deep heavy oil reservoir and achieving the sustainable development of the oilfield.