页岩气运移证据及其动态富集模式——以四川盆地南部深层页岩气为例  

Migration evidence and dynamic enrichment model of shale gas:Take the deep shale gas in the southern Sichuan Basin as an example

作　　者：缪欢 姜振学[1,2] 吴建发 伍秋姿 石学文 邓泽[1,2,4,5] 唐相路 吴伟[3] 陶传奇 郑洪扬 MIAO Huan;JIANG Zhenxue;WU Jianfa;WU Qiuzi;SHI Xuewen;DENG Ze;TANG Xianglu;WU Wei;TAO Chuanqi;ZHENG Hongyang(National Key Laboratory of Petroleum Resources and Engineering//China University of Petroleum-Beijing,Beijing 102249,China;Unconventional Oil&Gas Science and Technology Research Institute,China University of Petroleum-Beijing,Beijing 102249,China;Shale Gas Gas Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan,6100051,China;PetroChinaResearch Institute of Petroleum Exploration&Development,Beijing 100083,China;CNPC Key Laboratory of Unconventional Oil andGas,Beijing 100083,China;School of Civil Engineering,Liaoning Petrochemical University,Fushun,Liaoning 113001,China)

机构地区：[1]油气资源与工程全国重点实验室•中国石油大学(北京) [2]中国石油大学(北京)非常规油气科学技术研究院 [3]中国石油西南油田公司页岩气研究院 [4]中国石油勘探开发研究院 [5]中国石油集团非常规油气重点实验室 [6]辽宁石油化工大学土木工程学院

出　　处：《天然气工业》2024年第5期29-44,共16页Natural Gas Industry

基　　金：国家自然科学基金项目“深层页岩纳米孔隙介质表面性质及其流体赋存的限域效应”(编号:42372144);“海相富气页岩低阻成因及其对含气性的控制机理”(编号:42072151);国家能源页岩气研发(实验)中心基金项目“川南深层页岩低电阻成因及其对含气性的影响”(编号:2022-KFKT-15)。

摘　　要：页岩气存在运移现象,但页岩气运移现象对页岩气富集的影响尚不明确。为了查明深层页岩气运移证据及其富集模式,以四川盆地南部下志留统龙马溪组深层页岩气藏为例,基于页岩气藏天然气地球化学特征、赋存于顺层低角度裂缝中方解石脉包裹体特征、储层孔隙结构,查明了页岩气运移通道及运移能力,并结合典型气藏解剖,划分了龙马溪组页岩气动态富集模式。研究结果表明:①页岩气藏流体势场指示运移方向与气体组分指示方向一致,表明页岩气存在运移现象,且赋存于顺层裂缝中的流体包裹体揭示了研究区龙马溪组页岩气存在2期运移,分别发生在生烃高峰和后期抬升阶段;②现今研究区龙马溪组页岩储层存在满足页岩气运移的孔隙,且龙马溪组页岩孔隙以满足菲克扩散的孔隙为主,其次为满足滑脱渗流的孔隙和满足达西渗流的孔隙;③页岩气运移对页岩气富集具有重要的影响,研究区可划分出高抬升过渡带富集型、断裂散失背斜过渡带富集型、断裂散失向斜核部富集型、高部位富集型、弱运移能力断裂散失型5种页岩气动态富集模式。结论认为,在地质历史时期,页岩气存在运移现象,多期次的运移现象决定了现今的页岩气富集程度与富集区的优选。Shale gas exhibits migration phenomena,but the impact of shale gas migration on shale gas enrichment has not been figured out.To determine the migration evidences and the enrichment model of deep shale gas,this paper takes the deep shale gas reservoir of Lower Silurian Longmaxi Formation in the southern Sichuan Basin as an example to clarify the shale gas migration channels and capacities,based on the natural gas geochemical characteristics of shale gas reservoir,the features of calcite vein inclusion in bed parallel low�angle fractures and the reservoir pore structures.Then,the dynamic enrichment models of Longmaxi Formation shale gas are classified by analyzing typical gas reservoirs.And the following research results are obtained.First,the migration direction indicated by the fluid potential field of the shale gas reservoir is consistent with that indicated by the gas component,which proves the existence of shale gas migration.In addition,the fluid inclusions in bed parallel fractures reveal two migration periods of the Longmaxi Formation shale gas in the study area,which happened in the peak hydrocarbons generation stage and the later uplift stage,respectively.Second,in the present�day Longmaxi Formation shale reservoir in the study area,there are pores available for shale gas migration.The pores in the Longmaxi Formation shale are primarily the pores for Fick diffusion and secondarily for slip flow and Darcy flow.Third,shale gas migration has significant effects on shale gas enrichment.There are five new dynamic enrichment models of shale gas in the study area,i.e.,high uplift transition zone enrichment model,fault loss and anticline transition zone enrichment model,fault loss and syncline core enrichment model,high position enrichment model,and weak migration fault loss model.In conclusion,shale gas migration occurred in the geological history,

关 键 词：四川盆地南部 下志留统 龙马溪组 深层页岩气 页岩气运移 动态富集模式 

分 类 号：TE122.1[石油与天然气工程—油气勘探]