CO_2驱注采工艺的应用与发展

Development and application of CO_2 flooding

CO_2驱是一项实现提高原油采收率和地质埋存双重目的、绿色环保的驱油技术,注采工程是其关键技术环节。为了进一步现场推广及应用,从注气工艺、采油工艺、防腐工艺、安全风险控制技术等方面总结了CO_2驱注采工艺的技术特点,指出了注采工艺主要问题是气窜和层间矛盾突出、高气油比条件下举升效率低、复杂条件下多因素影响腐蚀控制难度大、施工安全风险高等。通过分析,认为提高注采开发效果、降低注采工艺成本、保障注采生产安全是CO_2驱注采工艺的发展趋势,并提出了完善分层注气工艺、试验评价新型举升工艺、优化选缓蚀剂配方和加药工艺、建立CO_2驱安全风险管理体系的建议。

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 otheraspects. Gas channeling, severe inter-layer interferences, low lifting efficiencies under high GOR, difficulties in corrosion protectionunder complicated conditions and high risks in operation safety have been identified as major challenges in CO2 flooding operations. Researchresults 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.