Abstract: The produced fluid of binary complex flooding in Shengli Oilfield of SINOPEC was analyzed, and the state of polymer, petroleum sulfonate and surfactant at oil-water interface was investigated by molecular simulation method. The cationic polymer water purification agent was developed in laboratory and tested in Dongyi union station in Gudong oil production plant in Shengli Oilfield. The result showed that the oil content in the 1st settling tank decreased from 1900 mg/L to 1050-1250 mg/L, the oil content of external sewage was qualified, and the expected effect was achieved.

Key words: binary complex flooding, produced fluid, demulsification, separation of water and oil