酒泉盆地营尔凹陷下沟组砂岩蒙皂石膜形成机制  

Forming Mechanism of Smectite Coating of the Sandstones in Xiagou Formation of Ying'er Sag,Jiuquan Basin

作　　者：周晓峰 李景[4] 于均民 李淑琴 符国辉[4] 盛思璐 许瑞 ZHOU Xiaofeng;LI Jing;YU Junmin;LI Shuqin;FU Guohui;SHENG Silu;XU Rui(China University of Petroleum State Key Laboratory of Petroleum Resources and Prospecting, Beijing 102249, China;China University of PetroleumSchool of Petroleum Engineering, Beijing 102249, China;China University of Petroleum MOE Key Laboratory of Petroleum Engineering, Beijing 102249, China;Research Institute of Exploration and Development, YumenOilfield Company, PetroChina, Jiuquan, Gansu 735019, China)

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]中国石油大学石油工程学院,北京102249 [3]中国石油大学石油工程教育部重点实验室,北京102249 [4]中国石油玉门油田分公司勘探开发研究院,甘肃酒泉735019

出　　处：《新疆石油地质》2019年第2期168-173,共6页Xinjiang Petroleum Geology

基　　金：国家科技重大专项(2011ZX05013-006);中国石油科技重大专项(2013E-3305)

摘　　要：酒泉盆地营尔凹陷下沟组砂岩中以黏土膜形式赋存的蒙皂石是一种能够预测储集层物性的标型矿物。通过铸体薄片和扫描电镜技术对蒙皂石膜的赋存状态进行观察,研究其形成机制及对储集层物性的影响,为营尔凹陷下沟组油气勘探开发提供科学依据。研究表明,晶形差的蒙皂石以胶囊状依附在碎屑颗粒表面成为黏土膜,成膜物质来源于携带蒙皂石黏土微粒的下渗大气水,成膜时间为早成岩阶段A期的方解石胶结之后。蒙皂石膜与石英胶结物共生,石英胶结物以石英微粒散布或以石英次生加大边覆盖在蒙皂石膜表面。鉴于此,生长在孔隙壁上的蒙皂石膜不能抑制石英次生加大,其对砂岩孔隙的保存不具有建设性作用,但可以作为指示砂岩物性好坏的标型矿物。The smectite whose occurrence is the clay coating in the sandstone of Xiagou formation in Ying’er sag is a kind of typomorphic mineral which can be used to predict reservoir physical properties. Using cast thin section analysis and SEM technology, the paper observes the occurrence of smectite coating and studies its forming mechanism and the influences on reservoir physical properties, in order to provide scientific basis for hydrocarbon exploration and development in Xiagou formation of Ying’er sag. The study shows that the smectite with poor crystal shapes adhered to the surface of clastic particles like capsules and became clay coating. The coating material came from the infiltrated atmospheric water carrying clay particles and the coatingforming time was after the calcite cementation during the early diagenesis stage A. Smectite coating coexists with quartz cements and the quartz cements are sparsely distributed or cover the surface of the smectite coating as the secondary enlarged edges of quartz. Therefore, the smectite coating growing on the wall of pores can’t inhibit the secondary enlargement of quartz, and make no contributions to the preservation of pores in sandstones, but it is a good typomorphic mineral to indicate physical properties of sandstones.

关 键 词：酒泉盆地 营尔凹陷 下沟组 蒙皂石膜 标型矿物 大气水渗滤 石英次生加大 

分 类 号：TE112.221[石油与天然气工程—油气勘探]