天然气工业2025，Vol.45Issue(9)：92-103,12.DOI:10.3787/j.issn.1000-0976.2025.09.008
碳酸盐岩气藏注CO2混合体系提高天然气采收率与气窜控制机理
EGR and channeling control mechanisms of CO2 mixture injection into carbonate gas reservoirs
摘要
Abstract
CO2-enhanced gas recovery(CO2-EGR)is a critical technique of improving gas recovery and storing CO2.However,CO2 is primarily supplied from flue gas,tail gas or other sources,usually containing gas impurity like N2.Use of separated and purified CO2 in CO2-EGR will significantly increase the production cost.To understand the mechanism of CO2 mixture injection into carbonate gas reservoirs for enhanced recovery,CO2 mixture-based long-core displacement tests and CO2 channeling control tests were conducted.The CO2-EGR effect with a varying injection rate,injection timing and gas composition was investigated,the key factors controlling CO2-EGR were identified,and the impact of channeling control on EGR was analyzed.The following results are obtained.First,the CO2-EGR effect increases and then decreases as the injection rate increases.When the injection rate is higher than 0.05 mL/min,the displacement process leads to a rapid CO2 breakthrough,causing a reduction in EGR.Second,an earlier injection results in a higher CO2-EGR effect but lower ultimate recovery in the gas reservoir.Third,a descending order of EGR is witnessed for gas components as follows:CO2,CO2-N2 mixture,N2,and CO2-N2-O2 mixture.Particularly,CO2 injection yields the best recovery factor as high as 10.04%.The mixture with a low CO2 content,showing similar properties to CH4,induces an earlier breakthrough,leading to a reduction in enhanced recovery.Fourth,breakthrough timing and CH4 recovery rate have great impacts on CO2-EGR,and anti-channeling agent is added to delay the breakthrough and increasing the CH4 recovery rate.Fifth,addition of SDS(sodium dodecyl sulfate)and SDS+TMPDA(N,N,N',N'-Tetramethyl-1,3-propanediamine)increases the recovery factor to 11.99%and 13.24%,respectively.It is concluded that the tests conducted clarify the patterns and mechanisms by which gas composition and injection parameters affect CO2-EGR,providing a theoretical basis and valuable reference for injecting CO2 mixture into carbonate gas reservoirs for enhanced recovery.关键词
碳酸盐岩气藏/CO2-EGR/混合体系/长岩心驱替/提高采收率/防窜控制/机理Key words
Carbonate gas reservoir/CO2-EGR/Mixture/Long-core displacement/Recovery enhancement/Channeling control/Mechanism分类
能源科技引用本文复制引用
曹成,申彪,陈星宇,张烈辉,周守为,赵玉龙,文绍牧,李清平,张德平,胡勇..碳酸盐岩气藏注CO2混合体系提高天然气采收率与气窜控制机理[J].天然气工业,2025,45(9):92-103,12.基金项目
国家自然科学基金区域创新联合基金重点项目"四川盆地有水气藏CO2驱提高采收率及其有效封存研究"(编号:U23A2022)、四川省自然科学基金项目"深层海相碳酸盐岩气藏注CO2提高采收率协同碳封存机理研究"(编号:2025ZNSFSC1357)、重庆市自然科学基金面上项目"多元杂质影响下CO2-地层水-泥岩作用机理及盖层封闭性演化机制"(编号:CSTB2024NSCQ-MSX0951)、油气藏地质及开发工程全国重点实验室开放基金项目"咸水层含杂质CO2-水-岩作用机制与封存潜力评价方法研究"(编号:PLN2023-28). （编号:U23A2022）
