东营凹陷牛庄洼陷古近系不同纹层组合富碳酸盐页岩的微观储渗能力  

Microscopic storage and seepage capacities in laminated carbonaceous shale of Paleogene in Niuzhuang Sub-Sag,Dongying Sag

作　　者：孔政 程紫燕 乔俊程 张玉亮[3] 曾溅辉 王云鹤[3] 李静逸 刘姝宁 刘新龙 KONG Zheng;CHENG Ziyan;QIAO Juncheng;ZHANG Yuliang;ZENG Jianhui;WANG Yunhe;LI Jingyi;LIU Shuning;LIU Xinlong(State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Exploration and Development Research Institute,Shengli Oilfield Company,SINOPEC,Dongying 257015,China)

机构地区：[1]中国石油大学(北京)油气资源与工程全国重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石化胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《中国石油大学学报(自然科学版)》2025年第2期68-81,共14页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金青年基金项目(42302144);中央高校基本科研业务经费项目(2462023BJRC012)。

摘　　要：东营凹陷古近系纹层状富碳酸盐页岩中蕴含了可观的页岩油资源量,但岩相复杂、纹层结构多样,使得该类页岩储、渗非均质性强,“甜点”确定难度大。以东营凹陷牛庄洼陷沙三下、沙四上亚段纹层状富碳酸盐页岩为研究对象,通过镜下观察与地球化学测试对纹层组合特征进行研究,进而联合多种孔隙结构表征技术研究不同纹层组合类型页岩的微米—纳米孔缝系统特征及其差异。结果表明,牛庄地区主要存在Ⅰ类平行厚层碳酸盐-薄黏土矿物纹层组合、Ⅱ类平行等厚碳酸盐-含长英质黏土纹层组合和Ⅲ类不连续碳酸盐-含长英质黏土纹层组合3类组合类型。Ⅰ类纹层组合中粒间孔及微裂缝发育,400~600 nm的宏孔和微裂缝为主流通道;Ⅱ类页岩中晶间孔占比高,随碳酸盐纹层发育程度降低,主流通道半径降低至25~63 nm。Ⅲ类页岩中以晶间孔为主,介孔超过90%,主流通道集中在25~63 nm。纹层类型及组合控制了孔隙成因及其微观结构,是纹层状富碳酸盐页岩微观储渗能力差异的主要原因,有机质和矿物组成变化影响了介孔和宏孔发育及结构特征,加剧了储渗差异。The Paleogene laminated calcareous shale in the Dongying Depression contains abundant shale oil resources.However,its complex lithology,characterized by intricate textures and diverse mineral compositions,results in strong heterogeneities in storage and seepage capacities,making it challenging to identify the"sweet spots"for shale oil extraction.In this study,we analyze lamina features and their combinations through integrated microscopic observations and geochemical measurements of laminated carbonaceous shales from the Es_(3)^(x) -Es_(4)^(s) formations in the Dongying depression,Bohai Bay Basin.Furthermore,we employ combined pore structure characterization techniques to investigate the microstructures of pores and fractures in shales with different lamina combinations.The results reveal three types of lamina combinations,of which Type Ⅰ is a binary combination of parallelly thick carbonate lamina and thin clay mineral lamina,Type Ⅱ is a binary combination of parallelly carbonate lamina and felsic clay lamina with uniform thickness,and Type Ⅲ is a combination of discontinuous carbonate lamina and felsic clay lamina with uniform thickness.In Type Ⅰ laminated shale,intergranular pores,dissolution pores,and microcracks are well-developed,with macropores and microcracks(400-600 nm)serving as the primary seepage channels.In type Ⅱ laminations,the proportions of intragranular pores increases,and as the intensity of the carbonate lamina decreases,the radii of the main seepage channels shrink to 25-63 nm.In Type Ⅲ laminated shale,intragranular pores dominate the pore space,with mesopores accounting for more than 90%of the storage capacity.Pores and throats of 25-63 nm are the primary seepage channels.The structure and arrangement of the laminae are key factors influencing the storage and seepage capacities of laminated carbonaceous shales,as they control the genesis and microstructure of pores.Additionally,variations in organic matter and inorganic mineral content enhance these distinctions by affecting the

关 键 词：纹层状富碳酸盐页岩 纹层结构 微观储渗能力 微观非均质性 控制因素 

分 类 号：TE122.2[石油与天然气工程—油气勘探]