Research About Reducing Water Injection Pressure of Low Permeability Reservoir with Low Tension System

In the process of water injection development at low permeability oil field, water injection pressure rises gradually and some water wells are abnormal because of lowly reservoir permeability and porosity. Then the poor quality of water injection will lead to bad effect. Low tension system RSE composited by quaternary ammonium cationic Gemini surfactant and common surfactant OP-10 can reduce the oil-water interfacial tension to 10-3mN/m. When the concentration of the RSE system increased to 0.08%, system solution can change the rock oil-wet surface into weak water; Oil-water relative permeability curve also manifest the system can improve the formation of oil and water seepage ability. The experiment results demonstrate that low tension system RSE can greatly reduce water injection pressure and improve water injection development effect of low permeability oil field.