Dynamic evolution mechanism of water-bearing coal permeability and water film under stress

被引：0
|
作者：
Duan S. [1 ]
Li B. [1 ,2 ,3 ]
Cheng Q. [1 ]
Song H. [1 ]
机构：
[1] College of Mining, Guizhou University, Guiyang
[2] National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Area, Guizhou University, Guiyang
[3] Guizhou Key Laboratory of Comprehensive Utilization of Non-metallic Mineral Resources, Guiyang
来源：
Meitan Kexue Jishu/Coal Science and Technology (Peking) | 2023年 / 51卷 / 06期
关键词：
coal; dynamic water film; permeability model; pore geometry; slippage effect;
D O I：
10.13199/j.cnki.cst.2022-0493
中图分类号：
学科分类号：
摘要：
To explore coal permeability evolution mechanism under the comprehensive action of multiple factors including stress - adsorption - water and slippage effect, considering the coal deformation induced by stress - adsorption, the expression of water film thickness was corrected to quantitatively characterize the effective pore size, and based on this, the intensity of gas slippage effect of water-bearing coal was further quantified and the permeability model was established under the comprehensive action of multiple factors. Combined with experimental research to verify the reliability of permeability model, and then the evolution mechanism of coal permeability, water film and slippage factors under the comprehensive action of multiple factors was further revealed. The results show that under different water saturation conditions, the permeability decreases sharply first and then tends to flat with the increase of effective stress; under the same effective stress condition, the permeability decreases with the increase of water saturation. The water film thickness changes dynamically under the action of stress - adsorption - water, the water film thickness has a negative correlation with stress and adsorption, but a positive correlation with water saturation; the slippage factor increases gradually with the increase of water saturation, but the increase trend is gentle under low stress condition, and more sharply under high stress condition. In addition, based on the disjoining pressure of gas-liquid-solid surface, the expressions of dynamic water film in square and equilateral triangle under the effect of stress-adsorption were deduced, and the evolution mechanisms of gas permeability, water film and slip coefficient of pores with different geometric shapes are compared and analyzed. Due to the presence of corner holes, the order of water film thickness in pores of different geometric forms is circle > square > equilateral triangle from large to small, the order of permeability is opposite; the slippage factor in circular is larger than that in angular pore, while the slippage factor in square and equilateral triangle pore has little difference. © 2023 China Coal Society. All Rights Reserved.
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页码：91 / 100
页数：9
相关论文
共 29 条
  • [1] WANG Guofa, REN Shihua, PANG Yihui, Et al., Development achievements of China's coal industry during 13 th Five-Year Plan period and future prospects[J], Coal Science and Technology, 49, 9, (2021)
  • [2] ZHAO Yanlong, XIN Xiaolin, WANG Zhiming, Experimental study on stress sensitivity of coal and rock fracture permeability in eastern Yunnan and western Guizhou[J], Coal Science and Technology, 47, 8, (2019)
  • [3] ADHIKARY D P, GUO H., Measurement of longwall mining induced strata permeability[J], Geotechnical and Geological Engineering, 32, 3, (2014)
  • [4] LI J, LI X F, WU K L, Et al., Thickness and stability of water film confined inside nanoslits and nanocapillaries of shale and clay[J], International Journal of Coal Geology, 179, pp. 253-268, (2017)
  • [5] ZHANG Jianguo, WANG Man, ZHANG Guochuan, Et al., Prevention and control of deep dynamic disasters and resources green exploitation in Pingdingshan Mining Area[J], Coal Science and Technology, 51, 1, (2023)
  • [6] GHANIZADEH A, GASPARIK M, AMANN H A, Et al., Experimental study of fluid transport processes in the matrix system of the European organic-rich shales: Ⅱ. Posidonia Shale(Lower Toarcian, northern Germany)[J], International Journal of Coal Geology, 123, (2014)
  • [7] KLINKRNBERG L J., The permeability of porous media to liquids and gases[J], API Drilling and Production Practice, 23, 2, (1941)
  • [8] AFSHARPOOR A, JAVADPOUR F., Liquid slip flow in a network of shale noncircular nanopores[J], Fuel, 180, pp. 580-590, (2016)
  • [9] WANG X L, PAN J N, WANG K, Et al., Characterizing the shape, size, and distribution heterogeneity of pore-fractures in high rank coal based on X-ray CT image analysis and mercury intrusion porosimetry[J], Fuel, 282, (2020)
  • [10] DUAN Shulei, LI Bobo, LI Jianhua, Et al., Permeability evolution of water-bearing coal considering dynamic slippage effect[J], Chinese Journal of Rock Mechanics and Engineering, 41, 4, (2022)
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