Coupled model of seepage and deformation fields in power-law fracture-distributed coal seam

被引：0
|
作者：
Liu G. [1 ,2 ,3 ]
Ye D. [1 ,2 ]
Gao F. [1 ,2 ,3 ]
Yue F. [1 ,2 ,3 ]
Gao T. [1 ,2 ,3 ]
机构：
[1] State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou
[2] Mechanics and Civil Engineering Institute, China University of Mining and Technology, Xuzhou
[3] Laboratory of Mine Cooling and Coal-heat Integrated Exploitation, China University of Mining and Technology, Xuzhou
来源：
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | 2022年 / 41卷 / 03期
关键词：
Adsorption stress; Coal permeability; Coal structure; Fractal geometry; Mining engineering; Multi-field coupling model;
D O I：
10.13722/j.cnki.jrme.2021.0696
中图分类号：
学科分类号：
摘要：
Coal microstructure has a significant impact on gas production. However, current coalbed methane (CBM) extraction models fail to consider this factor. In order to quantify the influence of the coal seam microstructure on macroscopic seepage processes, a fracture-matrix seepage model is developed based on the power-law fractal permeability theory, which is able to simultaneously analyze the interaction between the coal seam microstructure and multi-physical field factors. This model defines the multi-physical field effects(including gas adsorption- desorption effect, seepage-induced reservoir deformation, coal matrix deformation, fracture-matrix interactions, etc.) as functions of the effective stress in the reservoir, which in turn operate on the reservoir porosity and the microstructure. Furthermore, the influence of the main structural parameters of the coal seam on the macroscopic permeability, including general power law exponent α, extremum crack length ratio r and maximum fracture length l, is investigated, and the spatial and temporal evolutions of coal seam deformation and permeability are also analyzed. The simulation results show that the structural parameters of the coal seam have a significant influence on the permeability. The permeability of coal is proportional to the extremum fracture length ratio and the maximum fracture length while is inversely proportional to the general power law exponent. Moreover, the maximum fracture length of the coal seam has a more significant effect on the coal seam permeability than the general power law exponent and the extremum fracture length ratio. © 2022, Science Press. All right reserved.
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页码：492 / 502
页数：10
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