干旱区生态环境知识资源中心(Arid): Experimental study on pore structure evolution of coal in macroscopic, mesoscopic, and microscopic scales during liquid nitrogen cyclic cold-shock fracturing

Arid

DOI	10.1016/j.fuel.2021.120150
	Experimental study on pore structure evolution of coal in macroscopic, mesoscopic, and microscopic scales during liquid nitrogen cyclic cold-shock fracturing
	Sun, Yong; Zhai, Cheng; Xu, Jizhao; Cong, Yuzhou; Zheng, Yangfeng
通讯作者	Zhai, C (corresponding author), China Univ Min & Technol, Key Lab Coal Methane & Fire Control, Minist Educ, Xuzhou 221116, Jiangsu, Peoples R China.
来源期刊	FUEL
ISSN	0016-2361
EISSN	1873-7153
出版年	2021
卷号	291
英文摘要	Liquid nitrogen cyclic cold shock is a new waterless fracturing method suitable for coal seams in arid areas. The pore structure of coal after cold shock plays a key role in gas drainage, but there is currently a lack of study combining macroscopic-mesoscopic-microscopic scale. Multiscale pore characterization will be helpful to clarify the damage mechanism of liquid nitrogen cold shock to coal. In this paper, the same coal samples were tested for ultrasonic inspection, stereomicroscopic imaging and nuclear magnetic resonance (NMR) after different cold shock times. The macroscopic damage were studied by ultrasonic wave; the changes of mesoscopic pores and fractures (0.1 - 10 mm) were studied by stereoscopic microimaging and digital image processing; the changes of microscopic pores (2 nm - 0.1 mm) were studied by NMR. Finally, the macroscopic - mesoscopic - microscopic pore characteristic parameters were coupled. The main results are as follows: With the increase of cold shock times, the P/S wave velocities decreased, the dynamic parameters decreased linearly, and the macroscopic damage of coal samples was obvious. The number of mesoscopic pores, surface porosity, and probability entropy increased. As can be seen from the T2 spectra of coal samples, the microscopic pores expanded and increased with cold shock times. The effective porosity increased, among which the increase of micropores contributed the most. The macroscopic wave velocity and dynamic parameters of coal samples were negatively correlated with porosities. The calculation models of T2 cutoff value were established by multiple linear regression analyses, which were in good agreement with the experimental values.
英文关键词	Liquid nitrogen fracturing Coal pore structure Ultrasonic velocity Stereomicroscopic imaging Nuclear magnetic resonance
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000651787400002
WOS关键词	MECHANICAL-PROPERTIES ; IMAGE
WOS类目	Energy & Fuels ; Engineering, Chemical
WOS研究方向	Energy & Fuels ; Engineering
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/350343
作者单位	[Sun, Yong; Zhai, Cheng; Xu, Jizhao; Cong, Yuzhou; Zheng, Yangfeng] China Univ Min & Technol, Key Lab Coal Methane & Fire Control, Minist Educ, Xuzhou 221116, Jiangsu, Peoples R China; [Sun, Yong; Zhai, Cheng; Xu, Jizhao; Cong, Yuzhou; Zheng, Yangfeng] China Univ Min & Technol, Sch Safety Engn, Xuzhou 221116, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Sun, Yong,Zhai, Cheng,Xu, Jizhao,et al. Experimental study on pore structure evolution of coal in macroscopic, mesoscopic, and microscopic scales during liquid nitrogen cyclic cold-shock fracturing[J],2021,291.
APA	Sun, Yong,Zhai, Cheng,Xu, Jizhao,Cong, Yuzhou,&Zheng, Yangfeng.(2021).Experimental study on pore structure evolution of coal in macroscopic, mesoscopic, and microscopic scales during liquid nitrogen cyclic cold-shock fracturing.FUEL,291.
MLA	Sun, Yong,et al."Experimental study on pore structure evolution of coal in macroscopic, mesoscopic, and microscopic scales during liquid nitrogen cyclic cold-shock fracturing".FUEL 291(2021).