超临界CO_2注入与页岩气储层相互作用的研究进展

Research progress of supercritical CO_2 injection and its interaction with shale gas reservoirs

超临界二氧化碳(scCO_2)具有密度接近液体、黏度接近气体的特点,把CO_2注入深部页岩层,利用scCO_2流体进行储层压裂改造,既可以实现CO_2地质存储,又能提高页岩气采收率(scCO_2-ESGR),受到当前学术界的广泛关注。文中综合调研scCO_2注入与页岩气储层相互作用的最新国内外研究资料,介绍了scCO_2与储层矿物之间发生的溶解、溶蚀和沉淀作用,以及scCO_2对储层有机质的萃取能力和储层渗透率变化的研究进展,讨论了scCO_2与储层地球化学反应和渗透率变化的影响因素,以期为今后实施CO_2封存和scCO_2-ESGR技术的进一步研究与应用提供参考。

The density of supercritical carbon dioxide（scCO2） is close to that of liquid, but its viscosity is close to that of gas.Injecting CO2 into deep shale formation and using the fluid of scCO2 to improve reservoir fracturing can not only realize geological storage for CO2 but also enhance the shale gas recovery（Enhanced Shale Gas Recovery, ESGR）, which has achieved wide public concern from present academia. In this paper, based on the latest research progress, the mineral dissolution, corrosion and precipitation happened between the scCO2 and reservoir is introduced; the extraction ability of scCO2 for organic matter in reservoir and the research progress of the reservoir permeability are presented; the influence factors of geochemical reaction between scCO2 and reservoir and permeability are discussed, which provides a reference for further research in implementation of CO2 sequestration and scCO2-ESGR of technology.