Abstract: The Zhoucheng Oilfield Duo I Formation, a oil-bearing reservoir area is small, scattered, low abundance of reserves, is currently in the water development in the late, residual oil quantitative characterization and effective excavation technology optimization has become the core depth stage of oilfield development. A integrated innovation of chemical flooding technology to improve the system of enhanced CO₂ recovery (Chemicals & Carbon-dioxide, 2C). Study on laboratory experiment and numerical simulation show that after water flooding into the washing agent greatly reduce surface tension, improve sweep range of residual oil displacement efficiency, overlap by injection of CO₂, carry on the washing agent positive rhythm oil sand body high part of the effective spread, improve the vertical displacement of residual oil for effect. 2C technology system coupling chemical oil by viscosity and CO₂ overlap expand spread the advantages of achieving high water cut period of oil displacement efficiency and the vertical sweep coefficient increase, significantly improve the ultimate oil recovery.