Fractal Analysis and Classification of Pore Structures of High-Rank Coal in Qinshui Basin, China

doi:10.3390/en15186766

CORC > 深海科学与工程研究所 > 中国科学院深海科学与工程研究所 > 深海科学研究部 > 深海地球物理与资源研究室

	Fractal Analysis and Classification of Pore Structures of High-Rank Coal in Qinshui Basin, China
	Zhao, Difei 5,6; Guo, Yinghai 2,6; Wang, Geoff 3; Guan, Xin 4; Zhou, Xueqing 1; Liu, Jing 2
刊名	ENERGIES
	2022-09-01
卷号	15 期号:18 页码:22
关键词	pore structure coal fractal classification coalbed methane microstructure
DOI	10.3390/en15186766
通讯作者	Zhao, Difei(6133@cumt.edu.cn)
英文摘要	The influence of high-rank coal's pore characteristics on the physical properties, gas-bearing properties, and exploitation of coal reservoirs is becoming more and more prominent. How to establish the classification to describe the pore networks combining quantitative and qualitative characteristics has emerged as a major problem, which may offer a scientific foundation to deepen the understanding of this issue. In this research, the structure and fractal characteristics of reservoir pores were determined after analyzing 20 high-rank coal samples from Xinjing Coal Mine in the Qinshui Basin with the application of the high-pressure mercury intrusion method (HPMI) and argon ion polishing-field emission scanning electron microscopy (AIP-FESEM). The results show that the tested coal samples were bipolar distributed, with transitional pores and micropores dominating the pore volume, followed by macropores. The Menger sponge fractal models manifested two or three distinct straight-line segments with demarcation points of 65 nm and 1000 nm. A natural classification with three major pore types of diffusion pores (D-pores), seepage pores (S-pores), and pico pores (P-pores), demarcated by pore size intervals of 65 nm and 1 nm and seven sub-types, was established to relate pores to pore networks based on these fractal characteristics and the kinetic characteristics of methane molecules. This classification scheme can characterize the relationship between pore types and the corresponding major occurrence and transport mechanisms of the gas. In addition, P-pores and D-pores are predominately nanoscale OM pores with three major genetic types of organic constituent interparticle pores (5-200 nm), metamorphic pores (<5 nm), and intermorphic pores (<5 nm). S-pores are more complex in origin and shape features, and the major types include outgas pores, plant tissue residual pores, mineral-related pores, and microfractures. The mean radius (Pa), total pore volume (Vt), apparent porosity (phi), and volume ratio of macro- and mesopores were positively correlated with the fractal dimension D1 of S-pores (>65 nm). Since fractal analysis is a more comprehensive characterization of reservoir structure and quantitatively reflects the pore structure, undulating state, and roughness of the inner surface, fractal parameters can be used as an important index to describe the pore structure characteristics of high-rank coal reservoirs.
资助项目	Natural Science Foundation of Jiangsu Province[BK20210521] ; Fundamental Research Funds for the Central Universities[2017CXNL03] ; National Natural Science Foundation of China[41772130/41974149] ; Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City[2021JJLH0017] ; Scientific Research Foundation of Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education (China University of Mining and Technology)[2015-007]
WOS关键词	CH4 ADSORPTION CAPACITY ; METHANE RESERVOIRS ; GAS-ADSORPTION ; QUANTITATIVE CHARACTERIZATION ; ELECTRON-MICROSCOPY ; SIZE DISTRIBUTIONS ; MERCURY INTRUSION ; SURFACE-AREA ; SCALE PORES ; FIB-SEM
WOS研究方向	Energy & Fuels
语种	英语
出版者	MDPI
WOS记录号	WOS:000857541700001
资助机构	Natural Science Foundation of Jiangsu Province ; Fundamental Research Funds for the Central Universities ; National Natural Science Foundation of China ; Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City ; Scientific Research Foundation of Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education (China University of Mining and Technology)
内容类型	期刊论文
源URL	[http://ir.idsse.ac.cn/handle/183446/9776]
专题	深海科学研究部_深海地球物理与资源研究室
通讯作者	Zhao, Difei
作者单位	1.Chinese Acad Sci, Inst Deep Sea Sci & Engn, Sanya 572000, Peoples R China 2.China Univ Min & Technol, Sch Resources & Geosci, Xuzhou 221116, Jiangsu, Peoples R China 3.Univ Queensland, Sch Chem Engn, Brisbane, Qld 4072, Australia 4.China Univ Min & Technol, Sch Safety Engn, Xuzhou 221116, Jiangsu, Peoples R China 5.China Univ Min & Technol, Artificial Intelligence Res Inst, Xuzhou 221116, Jiangsu, Peoples R China 6.China Univ Min & Technol, Key Lab Coalbed Methane Resources & Reservoir For, Minist Educ, Xuzhou 221008, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Difei,Guo, Yinghai,Wang, Geoff,et al. Fractal Analysis and Classification of Pore Structures of High-Rank Coal in Qinshui Basin, China[J]. ENERGIES,2022,15(18):22.
APA	Zhao, Difei,Guo, Yinghai,Wang, Geoff,Guan, Xin,Zhou, Xueqing,&Liu, Jing.(2022).Fractal Analysis and Classification of Pore Structures of High-Rank Coal in Qinshui Basin, China.ENERGIES,15(18),22.
MLA	Zhao, Difei,et al."Fractal Analysis and Classification of Pore Structures of High-Rank Coal in Qinshui Basin, China".ENERGIES 15.18(2022):22.