Abstract:According to the characteristics of high temperature reservoir in Henan oilfield, in-situ emulsification flooding system was developed at 95℃ and its performance was evaluated. The results showed that the selected surfactant had good solubilization ability of crude oil, which can form micro emulsion system with crude oil in situ, has ultra-low interfacial tension, good adsorption resistance and temperature resistance, and the oil washing efficiency was 78%. Considering the strong fluidity of the micro emulsion, the optimized temperature resistant polymer has high mobility control capability that under the water quality conditions of 0.2mg/L~0.4mg/L oxygen content and 15mg/L~20mg/L sulfur content, the viscosity retention rate that more than 100% can be achieved after aging at 95℃ for 60 days. The experiment of natural core flooding showed that the phase characteristics of the produced liquid and core slice pores in in-situ emulsification flooding were obvious, the heavy components of crude oil were effectively displaced, and all types of remaining oil were well used, which had the ability to form emulsification flooding in the whole process of displacement. Further variable concentration step injection combined with profile control slug injection can increase the recovery rate by 28.4% in heterogeneous core test. At present, the technology has entered the stage of pre-slug injection in the mine field, and the digital-analog predicted enhanced recovery rate of 8.06 percentage points.