川东南地区茅口组一段地质特征及天然气富集规律——以南川区块为例  

Geological Characteristics and Natural Gas Accumulation Law of First Memberof Maokou Formation in Southeast Sichuan:A Case Study of Nanchuan Block

作　　者：李佳欣 房大志 程泽虎 LI Jiaxin;FANG Dazhi;CHENG Zehu(Key Laboratory of Hubei Province for Petroleum Geochemistry and Environment(Resources and Environment School of Yangtze University)Wuhan,Hubei 430100,China;Chongqing Shale Gas Co.,Ltd,Sinopec,Chongqing 408400,China)

机构地区：[1]油气地球化学与环境湖北省重点实验室(长江大学资源与环境学院),湖北武汉430100 [2]中石化重庆页岩气有限公司,重庆408400

出　　处：《西安石油大学学报（自然科学版）》2023年第4期12-19,共8页Journal of Xi’an Shiyou University（Natural Science Edition）

基　　金：中国石化科技部项目“南川地区茅口组天然气富集主控因素研究与目标评价”(P21042-4)。

摘　　要：为进一步分析川东南地区茅口组产能差异大的根本原因,利用测井、岩心、薄片、地化资料及现场生产资料对南川区块茅口组碳酸盐岩地层的沉积岩石学特征、构造特征、不同井位产能特征进行系统分析,结果表明:茅口组自上而下沉积水体渐深,茅一段泥质质量分数平均高达14.3%,生烃条件最好,且储集空间类型以微裂缝和溶蚀孔为主,具备自生自储特征;研究区域内,茅口组地层在纵、横向上发育均较为完整,在构造背景条件下,茅一段后期改造形成大量构造缝和断层,断层附近因侧向遮挡条件差,气测显示往往不佳,但构造缝的沟通使得天然气运移聚积成藏。南川区块茅一段良好的生烃条件是成藏的基础,天然气的富集具有“构造控藏、裂缝控产”的规律,在远离断层并发育裂缝型储集体的区域试气效果较好。In order to understand the fundamental reason for the large difference in productivity of different gas wells in Maokou Formation in southeast Sichuan,the sedimentary petrology characteristics,structural characteristics and different well location productivity characteristics of Maokou Formation carbonate in Nanchuan block were systematically analyzed by means of logging,core,thin section,geochemical and on-site production data.The results show that:The first member of Maokou Formation is characterized by high mud content and good hydrocarbon generation conditions,moreover,its storage space is mainly microfractures and dissolution pores.Therefore,the first member of Maokou Formation has self-generation and self-storage condition.In the study area,the Maokou Formation has relatively complete development in both vertical and horizontal directions.Under the regional tectonic background,a large number of structural fractures and faults were formed in the later stage of the first member of Maokou Formation,gas logging show is often poor near the faults due to poor lateral seal condition,but the communication of tectonic fractures makes the natural gas migrate and accumulate.Therefore,the favorable hydrocarbon generation condition in the first member of Maokou Formation in Nanchuan block is the basis for natural gas accumulation,and the enrichment of the natural gas has the law of"tectonic controlling accumulation and fracture controlling productivity".There is good gas testing effect in areas far from faults and with developed fractured reservoirs.

关 键 词：地质特征 天然气富集规律 茅一段 南川区块 川东南地区 

分 类 号：TE122[石油与天然气工程—油气勘探]