南堡凹陷沙一段页岩岩相对孔隙结构的影响  

Effect of shale lithofacies on pore structure in the first member of Shahejie formation,Nanpu sag

作　　者：侯佳凯 刘小平[1,2] 刘国勇[3] 王建伟[3] 高永亮 孙彪 刘欢 化祖献 刘天 刘函汐 HOU Jiakai;LIU Xiaoping;LIU Guoyong;Wang Jianwei;GAO Yongliang;SUN Biao;LIU Huan;HUA Zuxian;LIU Tian;LIU Hanxi(State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;PetroChina Jidong Oilfield Company,Tangshan,Hebei 063004,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石油冀东油田分公司,河北唐山063004

出　　处：《中国矿业大学学报》2023年第1期98-112,共15页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(42072150)。

摘　　要：为了探究湖相页岩岩相对页岩储层发育及孔隙结构的影响,以渤海湾盆地南堡凹陷林雀次洼沙一段页岩为研究对象,采用X射线衍射(XRD)、场发射扫描电镜(FE-SEM)、氮气吸附及恒速压汞等手段,对沙一段岩相进行了识别与划分,并针对不同岩相页岩孔隙结构的主控因素展开了进一步实验与理论研究.建立了“有机质丰度—矿物组分—沉积构造三端元—三级次”岩相划分方案,明确了沙一段页岩的主要岩相类型及特征,利用阈值法处理电镜图像定量评价了页岩的孔隙数目、孔隙率等参数,总结出不同岩相页岩的主要孔隙类型,运用页岩孔隙比表面积、孔体积、孔喉半径比和孔隙度等孔隙结构参数实现了不同岩相页岩孔隙结构的定性与定量表征,认为不同岩相页岩的微观孔隙结构非均质性较强,岩相对孔隙结构的控制作用较为显著.研究表明:南堡凹陷沙一段主要发育中有机质长英质纹层状页岩、中有机质富长英混合质纹层状页岩、富有机质富黏土混合质块状页岩和贫有机质富碳酸盐混合质层状页岩4种岩相类型;中有机质长英质纹层状页岩和中有机质富长英混合质纹层状页岩储集空间类型多样,孔隙类型以粒间孔和有机质孔为主,孔隙开放程度较高,孔隙率范围为2%~7%,孔喉半径比为90~140,孔径分布多尺度性强,且大于100 nm的大尺度孔隙发育较好,为优势岩相;矿物组分是影响页岩储层孔隙发育的最主要因素,有机质丰度和沉积构造次之,适宜的石英含量可有效增大孔体积和孔隙度,较高的TOC可以显著增加孔隙的比表面积,纹层状构造的发育能够极大改善页岩的孔隙结构和渗流性能.In order to explore the lacustrine shale rock relatively shale reservoir development and the influence of pore structure,the shale of Es1in Linque sub-sag,Nanpu sag,Bohai Bay Basin is taken as the research object,using X-ray diffraction(XRD),FE-SEM,nitrogen adsorption and constant-rate mercury injection experiments,the shale lithofacies of the Es1were identified and divided,further experimental and theoretical studies are carried out on the main controlling factors of shale pore structure in different lithofacies.A lithofacies division scheme of“organic matter abundance,mineral composition,sedimentary structure,ternary plots and three classes”has been established,and the main lithofacies types and characteristics of Es1shales are clarified,using the method of threshold processing electron microscopy image of quantitative evaluation of the shale pore number and parameters such as porosity,summarizes the main pore types of different lithofacies shale,and the pore structure parameters,such as pore surface area,pore volume,pore throat radius ratio and porosity,were used to characterize the pore structure of shale with different lithofacies qualitatively and quantitatively,think the microscopic pore structure of shale with different lithofacies is highly heterogeneous,and the controlling effect of lithofacies relative pore structure is significant.The results show that:Four lithofacies types are mainly developed in the Es1of the Nanpu sag:medium organic matter felsic laminated shale,medium organic matter rich felsic mixed laminated shale,organic matter rich clay mixed massive shale and low organic matter rich carbonate mixed laminated shale;There are various reservoir space types in medium organic felsic laminated shale and the medium organic matter rich felsic mixed laminated shale and the pore types are mainly intergranular pores and organic pores,the porosity degree is relatively high,the porosity range is 2%—7%,and the pore-throat radius ratio range from 90 to 140,large scale pores larger than 100 nm are wel

关 键 词：页岩 岩相划分 孔隙结构 沙河街组 南堡凹陷 

分 类 号：P618.13[天文地球—矿床学]