东濮凹陷古近系沙河街组页岩油储层岩石学及微观孔隙结构特征  

Shale oil reservoir of the Palaeogene Shahejie Formation in the Dongpu Sag:Petrology and pore microstructural characteristics

作　　者：彭君[1] 孙宁亮 鹿坤 徐云龙[1] 陈发亮[1] PENG Jun;SUN Ningliang;LU Kun;XU Yunlong;CHEN Faliang(Exploration and Development Research Institute,Zhongyuan Oilfield Company,SINOPEC,Puyang 457001,China;School of Resources and Civil Engineering,Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang 110819,China;Henan University of Urban Construction,Pingdingshan 467041,China)

机构地区：[1]中国石化中原油田分公司勘探开发研究院,河南濮阳457001 [2]东北大学深部金属矿山安全开采教育部重点实验室资源与土木工程学院,辽宁沈阳110819 [3]河南城建学院,河南平顶山467041

出　　处：《地学前缘》2023年第4期128-141,共14页Earth Science Frontiers

基　　金：国家科技重大专项课题“东濮凹陷油气富集规律与增储领域(2016ZX05006-004)”。

摘　　要：泥页岩的岩石学及微观孔隙结构特征是评价页岩油气储集性能的关键指标。通过岩心观察、薄片鉴定、扫描电镜、压汞-液氮吸附联合测定及微米CT三维重构等实验分析,对东濮凹陷沙河街组页岩油储层的岩石学特征、岩相类型、孔缝类型、孔喉分布及含油性特征等进行研究。实验分析结果表明,东濮页岩油储层矿物组分主要为黏土矿物、碳酸盐矿物,含有少量长英质矿物,主要的岩相类型包括纹层状灰岩相、纹层状黏土岩相、纹层状灰质细粒混合岩相、纹层状黏土质细粒混合岩相、块状黏土岩相和块状白云岩相;储集空间包括晶间孔、粒内溶蚀孔、黏土矿物晶间孔及有机质孔,微裂缝可分为成岩缝和构造缝,纹层状灰岩相和纹层状灰质细粒混合岩相的储集空间类型多样,储集空间相对较大。岩相和层理构造是影响储层孔隙发育及优劣的重要因素,纹层状灰质细粒混合岩、纹层状灰岩相及纹层状黏土质细粒混合相孔隙尺寸大,孔喉连通性较好,裂缝较为发育,同时具有好的含油性及可动性,其中以纹层状灰岩相最优,它们是东濮凹陷页岩油重点勘探对象。Shale petrology and pore microstructures are key performance evaluation indicators for shale oil and gas reservoirs.In this study,the petrological and oil compositional characteristics of shale oil reservoir and reservoir lithofacies types,pore/fracture types and pore-throat distribution in the Shahejie Formation in the Dongpu Sag are investigated by core observation,thin section analysis,scanning electron microscopy,mercury injection-liquid nitrogen adsorption and microCT-guided 3D reconstruction methods.Results show that the shale oil reservoir contains mainly clay and carbonate minerals and some felsic minerals.The main lithofacies includes laminated limestone/clay stone/calcareous fine-grained mixed rocks/argillaceous fine-grained mixed rocks,and massive clay stone/dolomite.The reservoir pore space is mainly provided by a combination of intergranular/intragranular dissolution/clay mineral intergranular/organic pores.The microfractures can be divides into diagenetic and tectonic fractures,and the laminated limestone/calcareous fine-grained mixed rocks developed various high porosity pore spaces.Lithofacies and bedding structure are important factors influencing pore development and pore quality.Laminated rocks,except clay stone,possess large pore space and show good pore connectivity,relatively developed microfractures and high oil content and mobility,and laminated limestone is the most favorable lithofacies.These rocks are key shale oil exploration targets in the Dongpu Sag.

关 键 词：页岩油 细粒沉积岩 岩石学特征 微观储层 东濮凹陷 

分 类 号：P618.130.2[天文地球—矿床学] P588.2[天文地球—地质学]