CH4 diffusion in intra-pore of montmorillonite: From self-diffusion to fick-diffusion

doi:10.1016/j.petrol.2020.107977

	CH4 diffusion in intra-pore of montmorillonite: From self-diffusion to fick-diffusion
	Hu, Haixiang 2; Xing, Yanfei 2; Wang, Bin 2; Lv, Yinghui 1; Zhang, Qiang 2; Li, Xiaoyong 3
刊名	JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
	2021-02-01
卷号	197 页码:9
关键词	Shale gas Diffusion Fick diffusivity Clay Molecular simulation
ISSN号	0920-4105
DOI	10.1016/j.petrol.2020.107977
英文摘要	Given the low permeability of clay (the main component of shale), diffusion is the main method for transport of methane in shale. Diffusion is a slower process than flow and permeation. Therefore, diffusion is a rate-controlling step during shale gas extraction. Diffusion of CH4 in clay mineral with water is investigated in detail. Dependences of self-diffusivity, Maxwell-Stefan (M-S) diffusivity and Fick diffusivity on various geological conditions are discussed. The practically important Fick diffusivity of methane in montmorillonite is calculated through molecular dynamics for the first time. Results show that self-diffusivity conventionally increases with temperature and its dependence on methane concentration follows the similar behavior of dependence on temperature. However, self-diffusivity displays a maximum at the water concentration of 2.5 molecules/unit-cell. The displacement distribution of CH4 calculated from molecule trajectory follows a logarithmic normal distribution, whose mean reaches the maximum at the same water concentration, resulting in the above-mentioned unusual behavior of self-diffusivity. M-S and Fick diffusivities go up with CH4 concentration and temperature while peak at the water content of 3.125 molecules/unit-cell. On the basis of self-diffusivity and M-S diffusivity, diffusion correlation parameter, D-ii, among methane molecules is computed. The diffusion correlation increases with methane concentration, water content, and temperature. Consequently, high methane concentration, temperature and moderately increasing water content result in fast methane diffusion, whereas excessively high water concentration hinders methane diffusion.
资助项目	National Key Research and Development Program[2016YFB0600805]
WOS研究方向	Energy & Fuels ; Engineering
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000604415500028
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/25557]
专题	中科院武汉岩土力学所
通讯作者	Hu, Haixiang; Wang, Bin
作者单位	1.Univ Jinan, Sch Civil Engn & Architecture, Jinan 250022, Shandong, Peoples R China 2.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Hubei, Peoples R China 3.Changjiang Wuhan Waterway Bur, Wuhan 434000, Hubei, Peoples R China
推荐引用方式 GB/T 7714	Hu, Haixiang,Xing, Yanfei,Wang, Bin,et al. CH4 diffusion in intra-pore of montmorillonite: From self-diffusion to fick-diffusion[J]. JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING,2021,197:9.
APA	Hu, Haixiang,Xing, Yanfei,Wang, Bin,Lv, Yinghui,Zhang, Qiang,&Li, Xiaoyong.(2021).CH4 diffusion in intra-pore of montmorillonite: From self-diffusion to fick-diffusion.JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING,197,9.
MLA	Hu, Haixiang,et al."CH4 diffusion in intra-pore of montmorillonite: From self-diffusion to fick-diffusion".JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 197(2021):9.