Based on the dynamic expressions of permeability and porosity of the coal seam derived in the paper, a multiphysical field coupling numerical model of gas migration under the interaction of stress field and seepage field was established. The gas drainage project #3 Coal Seam operated by Sima Coal Industry Co., Ltd., was selected as the study object. Taking different drainage time periods in various positions of drainage holes into consideration, combined with the advance situation of the 1207 working face in the Sima Coal Mine, a mixed layout gas drainage scheme featured with the effective borehole spacing was obtained through the COMSOL multiphysics simulation. In addition, a series of field industrial tests were performed to validate the research result, revealing that comprehensively considering the extraction time of coal and optimizing the layout of extraction boreholes can effectively improve the engineering economic benefits.

中文翻译：

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基于有效井距的司马煤矿瓦斯抽采优化案例研究

基于本文推导的煤层渗透率和孔隙度动态表达式，建立了应力场与渗流场相互作用下气体运移的多物理场耦合数值模型。以司马煤业有限公司经营的#3煤层瓦斯抽采工程为研究对象。考虑到各个排孔位置不同排采时间段，结合司马煤矿1207工作面的推进情况，通过COMSOL多物理场仿真，得到了以有效井距为特征的混合布置瓦斯抽放方案。此外，还进行了一系列现场工业试验以验证研究结果，