Research on adsorption and permeability mechanism of coal seams considering influence of anisotropy

doi:10.16265/j.cnki.issn1003-3033.2020.02.007

Abstract

Abstract: In order to explore the anisotropic seepage mechanism of coal seams, an adsorption model was established by analyzing its adsorption characteristics and the amount of adsorption deformation was calculated. Furthermore, the contribution of adsorption to permeability was quantified. On this basis, the anisotropic seepage characteristics of coal seams were analyzed. An anisotropic permeability model with coupling effect of stress and slippage effect was further constructed, and its applicability was verified by experimental data. The results show that the coal seam gas adsorption process is affected by sorption-induced deformation and external stress and there are differences in gas absorption amount in different directions, that during the increase of pore pressure, the gas adsorption curve in each direction shows a trend of increasing first and then flattening out, that under the combined effect of effective stress, pore pressure and slippage effect, the permeability of coal seams in all directions shows a decreasing trend and then a gentle change, and that considering the coupling effect of stress and slippage, the calculated curve of the anisotropic permeability model of the coal seam is in good agreement with the experimental value, which verifies the applicability of the model.

Key words: anisotropic, pore pressure, adsorption model, coal seam, permeability

CLC Number:

X936

LI Bobo, LI Jianhua, YANG Kang , REN Chonghong, WANG Bin. Research on adsorption and permeability mechanism of coal seams considering influence of anisotropy[J]. China Safety Science Journal, 2020, 30(2): 41-46.

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