Research and Application of High Efficiency Lifting Technology of Gas Detection Wells of CO2 Flooding

The lifting process design of CO2 flooding test area in Y oilfield was lifted by conventional rod pump. After gas was detected in the oil well, the pump efficiency of conventional pump decreased significantly and the production was greatly affected. Therefore, different anti-gas lifting technologies were studied and field tests were carried out. Through laboratory tests and numerical simulation, the flow state of CO2 flooding oil Wells was systematically analyzed, and the gas separation efficiency experiments of multistage gravity separation gas anchor, multifunctional integrated gas anchor and gas-liquid separation anti-air pump were carried out under different gas-liquid ratios, and compared with the field application situation. The results show that the existing anti-gas lifting technology can satisfy the normal production of Wells with gas-liquid ratio below 250 m3/m3. The multistage gravity separation gas anchor is not as effective as the multifunctional integrated gas anchor. Different structures of multifunctional integral gas anchor have obvious differences in gas prevention effect. Gas-liquid separation anti-air pump can prevent the occurrence of gas lock, but use alone can not play a role in improving pump efficiency. For fractured gas detection wells, the ratio of gas to liquid rises faster after gas detection wells, and the basic liquid after gas channeling, all the anti-gas lifting technology applied at present can not play a role. The research results can be used for reference in the selection of lifting technology in similar situations.