鄂西地区深层页岩气储层岩相孔隙结构特征差异及其控制因素--以YT1和YT3井五峰—龙马溪组页岩为例  

Characteristics and controlling factors of pore structure in different lithofacies of deep shale gas reservoirs:a case study of Wufeng-Longmaxi Formation shales from wells YT1 and Yt3 in Western Hubei

作　　者：吴泽宇 孙梦迪 蒋恕 张介辉 梁兴 王高成 白亮飞 孙良卫[4] WU Zeyu;SUN Mengdi;JIANG Shu;ZHANG Jiehui;LIANG Xing;WANG Gaocheng;BAI Liangfei;SUN Liangwei(Key Laboratory of Tectonics and Petroleum Resources,Ministry of Education,China University of Geosciences,Wuhan,Hubei 430074,China;Key Laboratory of Continental Shale Oil and Gas Accumulation and Efficient Development,Ministry of Education,Northeast Petroleum University,Daqing,Heilongjiang 163318,China;PetroChina Zhejiang Oilfield Company,Hangzhou,Zhejiang 311100,China;Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang,Sichuan 621999,China)

机构地区：[1]中国地质大学(武汉)构造与油气资源教育部重点实验室,湖北武汉430074 [2]东北石油大学陆相页岩油气成藏及高效开发教育部重点实验室,黑龙江大庆163318 [3]中国石油浙江油田分公司,浙江杭州311100 [4]中国工程物理研究院中子物理学重点实验室和核物理与化学研究所,四川绵阳621999

出　　处：《东北石油大学学报》2023年第1期15-29,I0002,I0003,共17页Journal of Northeast Petroleum University

基　　金：国家自然科学基金项目(42272159);国家自然科学基金项目(41802146);中国石油天然气集团公司重大现场试验项目(2019F-31)。

摘　　要：岩相页岩孔隙结构是影响页岩气储集及运移能力的重要因素。以鄂西地区五峰—龙马溪组深层页岩为例,采用小角中子散射、高压压汞和场发射扫描电镜等实验方法,对比不同岩相页岩孔隙结构特征,明确不同岩相页岩孔隙结构特征差异及其控制因素。结果表明:鄂西地区五峰—龙马溪组页岩划分为高有机质硅质页岩岩相、中有机质硅质页岩岩相和低有机质黏土/混合质页岩岩相,不同岩相总孔隙度为1.76%~4.27%;高有机质硅质页岩和中有机质硅质页岩储集空间以有机孔为主,低有机质黏土/混合质页岩储集空间以无机孔为主,微裂缝发育程度为高有机质硅质页岩>中有机质硅质页岩>低有机质黏土/混合质页岩;有机质丰度和矿物组分是不同岩相页岩孔隙结构差异主控因素,随总有机碳质量分数和硅质矿物质量分数降低,有机孔密度和孔径显著下降,孔隙结构非均质性减弱,微裂缝发育程度逐渐降低。高有机质硅质页岩相具有较强生烃潜力,微裂缝发育程度较高,为研究区段最优页岩相。总有机碳质量分数和矿物组分是五峰—龙马溪组深层页岩气储层不同岩相孔隙结构特征差异关键因素,高有机质硅质页岩相为研究区段最优页岩相。该结果为鄂西地区下寒武统五峰—龙马溪组深层页岩气储层评价和有利区预测提供支持。The pore structure of shale with different lithofacies is an important factor affecting the reservoir and migration ability of shale gas.Taking Wufeng-Longmaxi Formation deep shales in Western Hubei as an example,small angle neutron scattering,high pressure mercury injection and field emission scanning electron microscopy were used to compare the pore structure characteristics of different lithofacies shales,and to determine the differences and controlling factors of pore structure of different lithofacies shales.The results show that the Wufeng-Longmaxi Formation in Western Hubei can be divided into high organic siliceous shale facies,medium organic siliceous shale facies and low organic clay or hybrid shale facies.The total porosity of different lithofacies ranges from 1.76%to 4.27%.The reservoir space of high organic matter siliceous shale and middle organic matter siliceous shale is dominated by organic pores.The reservoir space of low organic matter clay/hybrid shale is dominated by inorganic pores.The degree of microfracture development from high to low is high organic matter siliceous shale,middle organic matter siliceous shale and low organic clay/hybrid shale.The abundance of organic matter and mineral composition are the main controlling factors for the difference of pore structure of different lithofacies shales.With the decrease of organic carbon mass fraction and silica mineral mass fraction,the density and size of organic pores decrease significantly,while the heterogeneity of pore structure is weakened,and the degree of microfracture development also decreases gradually.The siliceous shale facies with high organic matter has higher hydrocarbon potential and higher micro-fracture development,which is the best shale facies in the study area.The organic carbon mass fraction and mineral composition are the key factors for the difference of pore system characteristics of different lithofacies in the Wufeng-Longmaxi Formation deep shale gas reservoir.The siliceous shale lithofacies with high organic matt

关 键 词：孔隙结构特征 控制因素 储层评价 小角中子散射实验 高压压汞实验 场发射扫描电镜实验 深层页岩气 五峰—龙马溪组 鄂西地区 

分 类 号：TE122.1[石油与天然气工程—油气勘探]