渤海湾盆地东濮凹陷沙三段泥页岩储层孔隙微观特征及其对油气滞留的意义  

Microscopic characteristics of pores in Es^3 shales and its significances for hydrocarbon retention in Dongpu Sag,Bohai Bay Basin

作　　者：邵新荷 庞雄奇[1,2] 胡涛[1,2] 徐田武[3] 徐源[1,2] 唐令 李慧[1,2] 李龙龙 Shao Xinhe;Pang Xiongqi;Hu Tao;Xu Tianwu;Xu Yuan;Tang Ling;Li Hui;Li Longlong(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Zhongyuan Oilfield Company Ltd., SINOPEC,Puyang,Henan 457001,China;Unconventional Natural Gas Institute,China University of Petroluem(Beijing), Beijing 102249,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]中国石化中原油田分公司,河南濮阳457001 [4]中国石油大学(北京)非常规天然气研究院,北京102249

出　　处：《石油与天然气地质》2019年第1期67-77,共11页Oil & Gas Geology

基　　金：中国石化中原油田分公司科技项目(P15022)

摘　　要：结合基础地化特征,对渤海湾盆地沙三段泥页岩进行XRD全岩矿物测试、镜下薄片鉴定和扫描电镜观察、低温氮气吸附实验,分析泥页岩储层孔隙空间的微观结构特征,并在此基础上研究沙三段泥页岩储集空间发育的影响因素,阐述孔隙发育对泥页岩油气富集的意义。结果表明:东濮凹陷沙三段泥页岩可划分为粉砂质泥页岩、灰质泥页岩和膏质泥页岩,其地化特征非均质性很强,显示出油气在沙三段泥页岩中的富集特征十分复杂。沙三段泥页岩中发育有粒间孔隙、粒内孔隙、有机孔及裂缝,不同岩性中的主要孔隙类型及孔隙分布存在差异。低压氮气吸附实验显示出沙三段泥页岩孔径分布体系可分为微孔主导、大孔主导和多孔径共控3种孔隙结构。沉积作用及成岩作用对沙三段泥页岩孔隙网络的发育均有影响,沉积环境为不同类型孔隙在各个岩性中的发育奠定基础,成岩作用在泥页岩埋藏过程中对孔隙网络起改造作用,大孔隙和微裂缝为液态烃及游离气的主要富集场所,微孔及介孔能够为吸附气提供吸附位,溶解气对于页岩油的开发具有重要意义。The E s 3 shales in Dongpu Sag were studied with XRD analysis,thin section and SEM observation,and low-temperature nitrogen adsorption experiment based on their basic geochemical characteristics.Microscopic characteristics of shale pores were analyzed,and thus controlling factors of shale pore development and its significance for hydrocarbon retention in shales have been identified.Results show:the E s 3 shales in Dongpu Sag can be classified into silty shales,calcareous shales and gypsum shales according to their mineral compositions;the strong heterogeneity in shales’geochemical characteristics reflects a complex hydrocarbon retention pattern in E s 3 shales;several pore types including interparticle,intraparticle and organic-matter pores and fractures,are identified in E s 3 shales with different lithologies dominated by different pore types;the pore systems in E s 3 shales can be dominated by micropores,macropores,or pores of multiple diameters based on low-pressure nitrogen adsorption experiment;pore development in E s 3 shales is affected by both deposition and diagenesis,with deposition environment laying the foundation for pore development in various lithologies and diagenesis modifying pore structures during shale burial,respectively;oil and free gas mainly accumulate in large pores and microfractures,and micro-and meso-pores provide sites for adsorbed gas,while solution gas is of great significance to develop shale oil/gas resources.

关 键 词：微观孔隙特征 油气富集 泥页岩 沙三段 东濮凹陷 渤海湾盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]