Development and application of CO2 flooding

As an environment-friendly EOR technology, CO2 flooding can effectively enhance oil recovery and recoverable geologic reserve, during which injection and production are key processes. To further promote on-site application of CO2 flooding, technical features of CO2 flooding have been summarized with regard to gas injection, oil production, corrosion protection, risk control and other aspects. Gas channeling, severe inter-layer interferences, low lifting efficiencies under high GOR, difficulties in corrosion protection under complicated conditions and high risks in operation safety have been identified as major challenges in CO2 flooding operations. Research results show improvement of production performances, reduction of operation costs and control of operation risks are key points and developing trends in the process of CO2 flooding. In addition, advices have been proposed related to enhancement of separate-layer gas flooding, innovative lifting technologies, optimization of additive systems and processes and construction of risk control system for CO2 flooding operations.