摘要
本文以黔西北地区海相页岩层系牛蹄塘组、龙马溪组及海陆过渡相页岩层系龙潭组为研究对象,在孔隙特征分析和低温氮气吸附-脱附实验的基础上,对比研究深海陆棚相、浅海陆棚相以及潮坪-泻湖相泥页岩的孔隙分形维数特征。结果显示:深海陆棚相泥页岩分形维数D1适中,分形维数D2较大;浅水陆棚相分形维数D1偏小,分形维数D2适中;潮坪-泻湖相分形维数D1、分形维数D2均较大。通过将分形维数D1、D2与主要地质参数进行相关关系研究认为:D1能够较好地区别各种沉积相孔隙结构的整体特征,能够表征泥页岩的均质性、孔隙体积、吸附能力等宏观特征,D2则能够较好表征泥页岩结构复杂程度等微观特征。综合研究成果认为:浅海陆棚相泥页岩岩石均质性较好,吸附能力一般,微孔不很发育,不利于页岩气富集,资源潜力较小;潮坪-泻湖相泥页岩岩石非均质性强,吸附能力强,微孔发育,有利于游离态、吸附态页岩气富集,孔隙结构复杂,但开采难度最大;深海陆棚相泥页岩均质性较好,吸附能力适中,微孔发育,有利于游离态页岩气富集,但孔隙结构复杂,开采难度偏大。深海陆棚相为目前研究价值最高、经济开发潜力最高的层系。
The objects of this study are marine shale of Niutitang and Longmaxi Formations and marine-continental transitional shale of Longtan Formation in Northwest Guizhou.A comparative study on fractal characteristics(D1 and D2)of pore among deep-sea,shallow-sea shelf and tidal flat-lagoon shale is made based on low temperature nitrogen adsorption desorption experiments.The results show that the deep-sea shelf shale has moderate D1,large D2;shallow-sea shelf shale has low D1,moderate D2;tidal flat-lagoon shale has high D1 and D2.Correlating these fractal characteristics with the main geological parameters suggests that D1 can describe the difference of pore structure characteristics in different sedimentary facies better while D2 can characterize the microscopic complexity of shale.A comprehensive analysis shows that the shallow-sea shelf shale has low heterogeneity,normal adsorption capacity,rudimentary microporous,low potential of shale gas.Tidal flat-lagoon shale has high heterogeneity,strong adsorption capacity,and is rich in microporous,conducive to the preservation of free and adsorption shale gas,but difficult to develop.Deep-sea shale has low heterogeneity,normal adsorption capacity,rich in microporous,conducive to the preservation of free and adsorption shale gas,but its pore structure is complex,not very easy to exploit.In sum,the deep-sea shelf shale has the highest value of study as well as the highest economic development potential among the three shale intervals in northwest Guizhou.
作者
张鹏
黄宇琪
张金川
刘洪洋
杨军伟
ZHANG Peng;HUANG Yuqi;ZHANG Jinchuan;LIU Hongyang;YANG Junwei(Liupanshui Normal University,Liupanshui,Guizhou553004;School of Energy,China University of Geosciences,Beijing100083)
出处
《地质与勘探》
CAS
CSCD
北大核心
2019年第4期1073-1081,共9页
Geology and Exploration
基金
贵州省科技厅项目(编号:黔科合基础[2017]1420)
贵州省教育厅青年科技人才成长项目(编号:黔教合KY字[2016]266号)联合资助
关键词
海相
海陆过渡相页岩
孔隙
分形维数
黔西北
marine facies
marine-continental
shale
pore
fractal characteristics
northwest Guizhou
