摘要
为研究纹层、夹层对海相页岩储层的影响,通过岩心研究、薄片鉴定、氩离子抛光扫描电镜等测试手段,对纹层、夹层发育层段的岩性、矿物组分、结构、物性以及成因等进行分析,并与页岩基质进行比较,得到如下认识纹层发育层段岩性为砂质、粉砂质、碳酸盐岩等;与页岩基质相比,脆性矿物的含量更高、储层物性更好、孔隙及微裂隙发育尺度更大,说明纹层、夹层可以改变储层的物性、增加微观储集空间,其与页岩孔隙裂隙系统的相互配合改变了页岩气形成后的运聚条件,并增加了地层中脆性矿物的总含量,相比龙马溪组中部,纹层、夹层发育的顶部及新滩组储层脆性矿物总含量增加15%~35%,但以陆源碎屑矿物为主。同时,海相环境中的粉砂质沉积为在非优质页岩储层段进行致密气勘探带来新思路。
Through the study of the Longmaxi formation shale reservoirs in southern Sichuan and Chongqing area,it was found that the shale reservoirs generally have different origins of laminae and interbeds.To study the effect of laminae and interbedded layers on marine shale reservoir,analyzing the lithology,mineral composition,structure,physical properties and genesis of the laminated and interbedded layers by means of thin identification and argon ion polishing SEM,comparing those with shale matrix,got the followings:The lithology of laminae and interbedded layers is sandy,silty and carbonate rocks.Compared with shale matrix,reservoirs with laminae and interbeds are developed with higher brittle mineral content,different reservoir properties and larger pores and micro-fractures.Laminae and interbeds changed the physical properties of reservoirs and increase micro-reservoir space.Their interaction with shale pore and fracture system changed the migration and accumulation of shale gas after formation,and effectively increase the total content of brittle minerals in the formation.Compared with the middle part of Longmaxi formation,the total content of brittle minerals in the top of Longmaxi formation and Xintan formation with laminae and interbeds developed increases by 15%~35%,but mainly terrigenous clastic minerals.At the same time,silty deposits in marine environment also bring new approaches for the exploration of tight gas in shale strata.
作者
王玉杰
赵迪斐
卢琪荣
张逸箫
刘静
郭英海
Wang Yujie;Zhao Difei;Lu Qirong;Zhang Yixiao;Liu Jing;Guo Yinghai(School of Resources and Earth Science, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China;Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education, China University of Mining and Technology, Xuzhou, Jiangsu 221008, China;Key Laboratory of Shale Gas Exploration, Ministry of Natural Resources (Chongqing Institute of Geology and Mineral Resources), Chongqing 401120, China;National and local joint Engineering Research Center for shale gas exploration and development (Chongqing Institute of Geology and Mineral Resources), Chongqing 401120, China)
出处
《非常规油气》
2020年第6期33-40,共8页
Unconventional Oil & Gas
基金
国家自然科学基金资助项目面上项目“海相页岩储层纳米级储集空间精细定量解剖”(41772130)
刘宝珺地学青年科学基金“五峰组-龙马溪组页岩沉积‘精细微相’特征及其对储层发育的控制”(DMSMX2019002)
煤层气资源与成藏过程教育部重点实验室(中国矿业大学)开放基金资助项目“非常规储层非均质性及其地质意义”(2015-007)
自然资源部页岩气资源勘查重点实验室开放课题“海相页岩储层纳米孔隙精细表征与多方法交叉量化评价技术体系”(KLSGE-MLR-202002)
国家大学生创新训练项目“渝东南地区五峰组-龙马溪组页岩储层沉积相精细划分及意义”(201910290021Z)
中国矿业大学人工智能研究院科技双创孵化中心创新训练项目“页岩储层精细微相及其地质意义”(CSA-2020-007)资助。
关键词
页岩气
粉砂质纹层
粉砂质夹层
龙马溪组
物性
脆性矿物
shale gas
silty laminae
silty interbeds
Longmaxi formation
physical properties
brittle minerals
