Coal permeability model and evolution law considering water influence

被引：0
|
作者：
Li B. [1 ,2 ,3 ]
Li J. [1 ]
Yang K. [1 ]
Ren C. [1 ]
Xu J. [4 ]
Gao Z. [1 ]
机构：
[1] College of Mining, Guizhou University, Guiyang
[2] The National Joint Engineering Laboratory for the Utilization of Dominant Mineral Resources in Karst Mountain Area, Guizhou University, Guiyang
[3] State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao
[4] State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing
来源：
Meitan Xuebao/Journal of the China Coal Society | 2019年 / 44卷 / 11期
关键词：
Coal; Permeability; Pore pressure; Slippage effect; Water film;
D O I：
10.13225/j.cnki.jccs.2018.1625
中图分类号：
学科分类号：
摘要：
Coal is usually in a state of coexistence of gas and water during the changing process of the mining environment. In order to explore the reaction mechanism between water and coal permeability, the coal containing gas heat-fluid-solid coupling device of three axis servo seepage and isothermal adsorption device was used to carry out the experimental studies on the permeability of the coal when the increased pore pressure are under different water contents. Based on the interaction between water film and pore surface, and the effect of disjoining pressure between water films, considering the contribution rate of compression deformation and slippage effect to coal seepage, a permeability model that considers the effects of moisture was constructed. Furthermore, the variation of coal adsorption and seepage under different water conditions is analyzed. The results show that ① under different water-bearing conditions, the adsorption amount of coal increases with the increase of pore pressure. With the increase of water content, the adsorption amount decreases gradually, and the sorption-induced deformation also has the same trend. At the same time, the adsorption deformation changes with the adsorption of coal. ② The water in the coal rock is easy to form an adsorption water film on the surface of the pore crack to occupy the channel of gas seepage. And gaseous and liquid water molecules can restrict gas flow. Therefore, gas flow decreases as the water content increases. Under the condition of constant water content, the permeability of coal decreases first and then decreases with the increase of pore pressure. Under constant pore pressure, the permeability decreases significantly with the increase of water content. ③ Considering the effects of compression deformation, sorption-induced deformation, water content and water film thickness on the fracture width, a permeability model under gas-water environment was constructed. The permeability value of coal is in good agreement with the measured data, which can better characterize the water-bearing law of coal permeability. Meanwhile, relevant research results also provide a theoretical guidance for the management of coal mine gas disasters. © 2019, Editorial Office of Journal of China Coal Society. All right reserved.
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页码：3396 / 3403
页数：7
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