Displacement oil performance evaluation of polymer enhanced foam flooding in high-temperature and high-salinity reservoirs

Aiming at the high temperature (90 ℃) and high salinity (TDS=95 994 mg/L) reservoirs, the injection mode, gas liquid ratio, profile control and field test of polymer enhanced foam flooding system (0.2 wt% PSDA+0.1 wt% TritonX-100+0.2 wt% KYPAM-Ⅱ+ formation water) were evaluated in this paper. The co-injection of gas and solution for foaming-in-site is the most effective mode, but the alternative injection of gas and solution is the worst. The gas liquid ratio may greatly affect the flooding efficiency. The optimized gas liquid ratio is proposed as 3:1 for co-injection mode at the reservoir condition. Results of dual cores flooding experiments indicate that the foam flooding can obviously increase oil recoveries of high and low permeability zones, the foam flooding has excellent profile control ability, polymer enhanced foam flooding can improve 15.3% average OOIP (original oil in place) recovery. The field test results show that the effect of enhance oil recovery rate by using foam flooding is significant in two wells group.