中国地质2024，Vol.51Issue(1)：57-72,16.DOI:10.12029/gc20210923001
黔东南地区牛蹄塘组页岩孔隙结构多尺度表征及其对页岩气富集的影响
Multi-scale characterization of shale pore structure of Niutitang Formation in southeastern Guizhou and its influence on shale gas enrichment
摘要
Abstract
This paper is the result of oil and gas exploration engineering. [Objective]It is necessary to study the pore structure characteristics of Niutitang Formation shale in Southeast Guizhou and its influence on shale gas enrichment,avoid unfavorable factors,and provide suggestions for shale gas exploration in Southeast Guizhou.[Methods]Multi-scale characterization of the shale micro-nano pore structure is carried out by means of focused ion beam scanning electron microscopy(FIB-SEM),FE-SEM,and nitrogen adsorption.Combined with the hydrocarbon generation and burial history of the Niutitang Formation shale in the study area,the relationship between tectonic movement and pore structure is studied,and its control effect on shale gas enrichment is analyzed.[Results]The Niutitang Formation shale mainly develops millimeter-scale micro-cracks,micron-scale pyrite intercrystalline pores and nano-scale organic pores,mainly ink bottle-shaped pores and slit pores with a flat plate structure,and the pore structure is complex.Combined with the results of FIB-SEM three-dimensional reconstruction,organic matter accounts for a relatively high proportion of shale,with a porosity of 0.04%-2.48%and a contribution rate of 14%-96%to the total porosity.The pyrite crystals co-existing with organic matter Pores are the main type of pores that communicate fractures,the shale gas in this area is dominated by undersaturated adsorbed gas,and the free gas content is low.[Conclusions]A large number of structural fractures in the Niutitang Formation shale have connected organic matter pores and pyrite intercrystalline pores,and changed the original pore structure,causing the in-situ accumulated shale gas to escape along the fractures,which is a key factor in the low gas content of the shale of the Niutitang Formation.Finding areas with moderate thermal evolution and well-preserved structures is a favorable direction for shale gas exploration on the periphery of paleo-uplifts.关键词
页岩气/孔隙结构/三维重构/古隆起周缘/保存条件/油气地质调查工程/黔东南地区Key words
shale gas/pore structure/three-dimensional reconstruction/periphery of paleo-uplift/preservation conditions/oil and gas exploration engineering/Southeast Guizhou分类
天文与地球科学引用本文复制引用
葛明娜,包书景,石砥石,马勇,张金川,张琴,张立勤,林燕华,王婷..黔东南地区牛蹄塘组页岩孔隙结构多尺度表征及其对页岩气富集的影响[J].中国地质,2024,51(1):57-72,16.基金项目
国家科技重大专项"页岩气资源评价方法与勘查技术攻关"(2016ZX05034)、国家自然科学基金重点项目(42130803)及中国地质调查局项目(DD20230257)联合资助.Supported by National Science and Technology Major Project"Shale gas resource evaluation methods and exploration techniques"(No.2016ZX05034),National Natural Science Foundation of China(No.42130803)and the project of China Geological Survey(No.DD20230257). （2016ZX05034）
