黔北凤冈地区下寒武统牛蹄塘组页岩孔隙结构特征及油气地质意义  

Characteristics of shale pore structure and its oil and gas geological significance of Lower Cambrian Niutitang Formation in Fenggang area,northern Guizhou

作　　者：朱彪 邹妞妞[1,2] 张大权 杜威 陈祎 ZHU Biao;ZOU Niuniu;ZHANG Daquan;DU Wei;CHEN Yi(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China;Key Laboratory of Karst Georesources and Environment,Ministry of Education,Guizhou University,Guiyang 550025,China;Key Laboratory of Unconventional Natural Gas Evaluation and Development in Complex Tectonic Areas,Ministry of Natural Resources,Guiyang 550004,China;Guizhou Engineering Research Institute of Oil&Gas Exploration and Development,Guiyang 550000,China)

机构地区：[1]贵州大学资源与环境工程学院,贵阳550025 [2]贵州大学喀斯特地质资源与环境教育部重点实验室,贵阳550025 [3]自然资源部复杂构造区非常规天然气评价与开发重点实验室,贵阳550004 [4]贵州省油气勘查开发工程研究院,贵阳550000

出　　处：《岩性油气藏》2024年第4期147-158,共12页Lithologic Reservoirs

基　　金：贵州省科技计划项目“黔北下寒武统牛蹄塘组页岩裂缝与页岩气控制作用”(编号:黔科合基础-ZK[2023]一般192);贵州省找矿突破战略行动重大协同创新项目“贵州省页岩气效益开发关键技术及工程试验”(编号:黔科合战略找矿[2022]ZD005);贵州省科技厅计划项目“黔北地区下寒武统牛蹄塘页岩孔隙连通性流体示踪研究”(编号:黔科合基础[2019]1119)联合资助。

摘　　要：利用全岩X射线衍射(XRD)、场发射扫描电镜(FE-SEM)、核磁共振(NMR)和低温氮气吸附实验方法多尺度定性-定量表征黔北凤冈地区永凤1井下寒武统牛蹄塘组页岩孔隙结构特征,并探讨其影响因素与油气地质意义。研究结果表明:(1)黔北凤冈地区下寒武统牛蹄塘组页岩矿物组成以石英、长石与黏土矿物为主,其次为碳酸盐矿物与黄铁矿;孔隙类型主要为有机质孔、粒间孔、粒内孔与微裂缝,有机质孔与黏土矿物粒间孔最为发育。(2)研究区牛蹄塘组页岩比表面积平均值为9.536 6 m^(2)/g,总孔体积平均值为0.009 02 cm^(3)/g,介孔体积平均值为0.007 95 cm^(3)/g,宏孔体积为0.000 37~0.004 58 cm^(3)/g,平均为0.001 07 cm^(3)/g,平均孔径为3.381~5.947 nm,介孔最为发育。页岩孔体积主要由介孔与宏孔贡献,比表面积主要由微孔与介孔贡献,微孔与介孔、宏孔连通性相对较差,介孔与宏孔连通性较好,孔隙形态主要为墨水瓶形、圆柱形和裂缝形。(3)研究区牛蹄塘组孔隙结构主要受TOC、黏土矿物与脆性矿物影响,TOC与黏土矿物对比表面积、总孔体积、介孔体积及孔隙度具有积极影响,脆性矿物则对比表面积、孔隙度、介孔体积具有消极影响。Using whole rock X-ray diffraction(XRD),field emission scanning electron microscopy(FE-SEM),nuclear magnetic resonance(NMR),and low-temperature nitrogen adsorption experimental methods,multi-scale qualitative and quantitative characterization of the pore structure characteristics of shale of Cambrian Niutitang Formation of well Yongfeng 1 in Fenggang area of northern Guizhou was carried out,and its influencing factors and oil and gas geological significance were discussed.The results show that:(1)The shale minerals of Lower Cambrian Niutitang Formation in Fenggang area of northern Guizhou are mainly composed of quartz,feldspar and clay minerals,followed by carbonate minerals and pyrite.The pore types are mainly organic matter pores,intergranular pores,intragranular pores and micro-cracks,with organic matter pores and clay mineral intergranular pores being the most developed.(2)The average specific surface area of the shale of Niutitang Formation in the study area is 9.5366 m^(2)/g.The average total pore volume is 0.00902 cm^(3)/g,the average mesopore volume is 0.00795 cm^(3)/g,the macropore volume is 0.00037-0.00458 cm^(3)/g,with an average value of 0.00107 cm^(3)/g,and the average pore size is 3.381-5.947 nm.The mesopores are the most developed.The pore volume of shale is mainly contributed by mesopores and macropores,and the specific surface area is mainly contributed by micropores and mesopores.The connectivity between micropores and mesopores and macropores is relatively poor,and the connectivity between mesopores and macropores is good.The pore shapes are mainly ink-bottle shaped,cylindrical shaped,and fracture shaped.(3)TOC,clay minerals and brittle minerals are the main factors controlling the pore structure of shale of Niutitang Formation in the study area.TOC and clay minerals have positive effects on specific surface area,total pore volume,mesopore volume and porosity,while brittle minerals have negative effects on specific surface area,porosity and mesopore volume.

关 键 词：孔隙结构 有机质孔 黏土矿物粒间孔 介孔 宏孔 页岩 牛蹄塘组 下寒武统 永凤1井 黔北凤冈地区 

分 类 号：TE122.23[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]