New Lifting Technology for CO2 Flooding Wells with High GOR in Caoshe Oilfield

In the process of CO2 flooding in the Caoshe Oilfield, the injected CO2 broke through to the producing wells through big channels, causing the GOR to rise and the pump efficiency to be reduced in a conventional tube pump. In consideration of such circumstances, the lifting technology for CO2 flooding wells with high GOR was studied. By developing the anti-gas jet pumps and the pumps with forced pulling rods, a new lifting technology for CO2 flooding wells with high GOR formed by combining lifting strings that have two-stage gas control functions, and taking the measures of anti-CO2 corrosion which are applicable to CO2 flooding wells. The technology was used in three wells in Caoshe Oilfield, North Jiangsu, and showed that the average pump efficiency was enhanced by 10.5 percent point, the and average daily oil production per well was increased by 2.0 tons. It indicates that the new lifting technology for CO2 flooding well with high GOR can solve the problem of low pump efficiency in CO2 flooding wells with high GOR in the Caoshe Oilfield, and reach the goal of increasing the pump efficiency and oil production, which provides a new technical approach for improving the overall oil recovery by means of CO2 flooding in the Caoshe Oilfield.