CO2增强页岩气开采及地质埋存的三维数值模拟OA北大核心CSTPCDEI
Three-dimensional numerical simulation of CO2 injection to enhance shale gas recovery and geological storage
将CO2 注入页岩储层中,既可以提高气藏天然气采收率,又可以达到CO2 地质埋存的目的,是实现减少碳排放的有效途径之一.页岩储层非均质性强,将CO2 注入页岩储层后,储层纵向非均质性对于CO2 增强CH4 开采效果的影响机理研究还存在不足.为此以四川盆地上奥陶统五峰组—下志留统龙马溪组页岩储层为对象,以考虑CO2 和CH4 竞争吸附的热—流—固多场耦合数值模拟方法为基础,建立了页岩非均质储层CO2 增强CH4 开采及地质埋存一体化三维数值模型,最后通过CO2 驱替CH4 室内实验结果验证该数值模拟方法的可靠性.研究结果表明:①当注入井所在层位保持不变时,随着开采井埋深增加,各小层内CH4 剩余量呈增加趋势,CO2 埋存量表现出逐渐减小的趋势;②当开采井所在层位保持不变时,各小层内CH4 的剩余量随注入井埋深的增加而减小,各小层内CO2 的埋存量随注采井纵向间距的增加而提高;③增加注采井纵向距离能够提高CH4 增产量和CO2 埋存量.结论认为,页岩对CO2 和CH4 有较强的竞争吸附特性,相关过程是一个复杂的热—流—固耦合过程,该基础理论模拟研究对注CO2 置换CH4 提高页岩气采收率并实现碳封存具有现实意义,且研究认识对今后相关技术的现场应用提供了理论支撑.
Injecting CO2 into shale reservoirs is an effective way to reduce carbon emissions,which can not only enhance the natural gas recovery of gas reservoirs,but also achieve the goal of CO2 geological storage.Shale reservoirs have strong heterogeneity,However,few researches have been carried out on the influential mechanisms of vertical reservoir heterogeneity on CO2 enhanced CH4 recovery effect after the injection of CO2 into shale reservoirs.Taking the Wufeng-Longmaxi Formation shale reservoir in the Sichuan Basin as the research object,this paper establishes a 3D numerical model of integrated CO2 enhanced CH4 recovery and geological storage in heterogeneous shale reservoir on the basis of the thermal-hydraulic-mechanical coupling numerical simulation method which takes into account the competitive adsorption of CO2 and CH4.In addition,the reliability of the numerical simulation method is verified through the laboratory experiment results of CO2 displacing CH4.And the following research results are obtained.First,if the injection well is kept in the same horizon,the remaining CH4 in each sublayer presents an increasing trend,and the CO2 storage presents the trend of decreasing gradually with the depth increase of the production well.Second,if the production well is kept in the same horizon,the remaining CH4 in each sublayer decreases with the depth increase of the injection well,and the CO2 storage in each sublayer increases with the increase of vertical spacing between the injection well and the production well.Third,increasing vertical spacing between the injection well and the production well can result in an increase in CH4 production increment and CO2 storage.In conclusion,shale has stronger competitive adsorption to CO2 and CH4,and the related process is a complex thermal-hydraulic-mechanical coupling process.The simulation study of this basic theory is of practical significance to CO2 injection to replace CH4 for enhancing shale gas recovery and CO2 storage.What's more,the research results provide a theoretical support for the field application of the related technologies in the future.
赵鹏;朱海燕;张丰收
地质灾害防治与地质环境保护国家重点实验室·成都理工大学油气藏地质及开发工程全国重点实验室·成都理工大学||成都理工大学能源学院同济大学土木工程学院
石油、天然气工程
CO2 增强页岩气开采CO2 地质埋存储层非均质性热—流—固多场耦合三维模型
CO2 enhanced shale gas recoveryCO2 geological storageReservoir heterogeneityThermal-hydraulic-mechanical coupling 3D model
《天然气工业》 2024 (004)
104-114 / 11
国家重点研发计划项目"CO2地质封存协同枯竭页岩储层增渗开采技术"(编号:2023YFE0110900)、"大型油气藏CO2压裂埋存全流程关键技术指标体系及标准化"(编号:2023YFF0614102);地质灾害防治与地质环境保护国家重点实验室自主研究课题"页岩基质损伤渗透-裂缝内多相流耦合裂缝扩展研究"(编号:SKLGP2022Z018).
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