渤海湾盆地东营凹陷细粒沉积微相对页岩油储层微观结构的控制作用  

Controlling effect of fine-grained sedimentary microfacies upon the microstructure of shale oil reservoirs in the Dongying Sag,Bohai Bay Basin

作　　者：张顺[1,2] 王永诗[1] 刘惠民[1] 陈世悦[3] 谭明友[4] 张云银[4] 郝雪峰[1] 谢忠怀[1] 

机构地区：[1]中国石化胜利油田分公司勘探开发研究院,山东东营257022 [2]中国石化胜利油田分公司博士后流动工作站,山东东营257022 [3]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [4]中国石化胜利油田分公司物探研究院,山东东营257022

出　　处：《石油与天然气地质》2016年第6期923-934,共12页Oil & Gas Geology

基　　金：国家自然科学基金项目(41372107);国家重点基础研究发展计划(973计划)项目(2014CB239102)

摘　　要：以渤海湾盆地东营凹陷古近系沙河街组三段下亚段泥页岩为研究对象,通过厘米级岩心观察描述、岩石薄片鉴定、X-射线衍射分析等,分析泥页岩基本沉积特征,划分岩相及微相类型,分析半深湖-深湖沉积微相平面和垂向分布特征。综合扫描电镜观察、激光共聚焦显微镜观察以及低温氮气吸附实验等,对储层的孔隙和裂缝成因、类型、形貌、孔径及孔隙分布等特征进行综合表征。结果表明,东营凹陷泥页岩矿物类型多样,以往作为优质烃源岩的细粒沉积岩,其实大部分属于碳酸盐岩范畴;储层孔隙、裂缝类型多样,孔隙存在多尺度性、孔隙结构复杂。不同微相的泥页岩储层微观结构特征存在差异,沉积微相对储层微观结构的控制作用主要表现在对储层矿物组成和组构、有机质的沉积和保存条件的控制,进而影响了孔隙类型及孔隙结构。平阔半深湖微相发育的泥页岩储层有机质含量较高,脆性矿物以方解石为主,孔隙和裂缝类型多样,孔隙连通性中等且孔隙的开放性较好,可视为页岩油勘探开发有利相带区。Shale samples from the lower third member of the Shahejie Formation of the Palaeogene in Dongying Sag were taken for a sedimentation characterization, a classification of lithologic facies and microfacies and an analysis of planar and vertical distributions of the shales of semi-deep and deep lacustrine facies through a centimeter-scale core descrip- tion, thin section identification and X-ray diffraction analyses of the samples. Such means as observations of SEM images and laser confocal microscope and experiments of low-temperature nitrogen adsorption were also resorted to study the gen- esis, types, morphology, size and distribution of pores and fissures in the samples. The results show various types of miner- als and the fine-grained sediments being regarded previously as high-quality source rocks are largely carbonates. It also indicates that there are various pore and fissure types and the pores are of multi-scales and have complicated structures. The shale reservoirs with different types of microfacies differ in micro-structures. The controlling effect of sedimentary mi- crofacies upon the micro-structure of reservoirs is mainly displayed in compositions and fabric of minerals, and deposition and preservation of organic matters, which further affect the types and structures of pores. The shale reservoirs developed in flat and semi-deep lacustrine facies are found to contain high content of organic matters, various types of rocks and brittle minerals dominated by calcite. They also harbor pores and fissures of various types. With fairly connected open pores, the reservoirs are considered to be potential exploration targets in the sag.

关 键 词：孔隙 储层微观结构 沉积微相 泥页岩 东营凹陷 渤海湾盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探]