Technology of Decreasing Injection Pressure and Increasing Injection Rate by Surfactant in CS block of Chaoyanggou Oilfield

摘要

The CS block of Chaoyanggou oilfield is a extra low-permeability reservoir. In the process of water flooding, some problems which influence exploitation effect are commonly found, such as high flooding pressure and insufficient injection in water wells. Based on the analysis of lithology and physical property of CS block, the formula were obtained by measuring the IFT of oil and surfactant solution. According to the core simulation experiments, the injection parameters were optimized. Results indicate that the IFT of the CS block oil and formula system is 8.16×10~(-3)mN/m, the best concentration of surfactant is 0.5%, the best injection volume is 0.5PV, the ratio of decreasing injecting pressure is 38.90%.