用模糊评判优选井位的CO2吞吐强化采油技术

Using fuzzy comprehensive evaluation model to screen CO_2 huff and puff well candidates for enhanced oil recovery

为提高单井注CO2吞吐强化采油措施的成功率,增加中低渗复杂小断块油藏的开发效益,结合国内外相关开发实例资料分析、理论研究结果,综合储层流体特性、油藏特性、储层岩石特性参数,建立了CO2吞吐井位筛选评价指标体系及其分级评价标准;基于模糊综合评判理论,提出了复杂断块油藏CO2吞吐井位筛选的具体方法、步骤。利用建立的方法,在对实际复杂断块油藏注CO2吞吐井位优选的基础上,选择合理的注采制度,进行注CO2吞吐强化采油开发实践。油田开发生产实践表明,采取模糊评判井位优选的单井CO2吞吐强化采油,降低了复杂断块低渗油藏措施实施的风险程度,提高了单井的开发效益。研究结果对油藏单井注CO2吞吐措施的实施提供了理论依据和技术支持,为相似油藏利用CO2吞吐进行强化采油提供了有益的借鉴。

To improve the success rate of CO2 enhanced recovery and development benefit of medium or low permeability small complex fault block reservoirs, this paper develops an evaluation index system and grading evaluation criteria of well location screening for CO2 huff and puff. This is based on the integration of many case studies and theoretical analysis at home and abroad, fluid properties, reservoir characteristics and rock properties. On this basis, the paper then puts forward concrete method and steps for well location screening using fuzzy synthetic evaluation theory. With this procedure, the well locations are selected and reasonable injection and production rates for a specific reservoir are assigned. Development practice reveals that introducing the fuzzy evaluation theory into CO： huff and puff well location screening can greatly reduce operation risks and enhance oil recovery. The findings of this study are of theoretical and technical significance for CO2 stimulation in similar reservoirs.