摘要
为探究顺层抽采条件下不同抽采参数对于瓦斯抽采效果的影响,以芦河煤业3号煤层为例,采用双重孔隙介质模型结合固体变形方程作为固体场控制方程,并采取Fick扩散与达西定律结合流体连续性方程作为流体场控制方程,利用COMSOL软件建立了瓦斯抽采多场耦合数值模型。探究了钻孔直径,抽采时间,抽采负压,钻孔间距影响下的瓦斯压力与有效抽采区变化规律。结果表明:瓦斯抽采效率随着钻孔直径的增加而提高。瓦斯压力随抽采时间的增加而降低,抽采前期钻孔有效抽采区的变化范围较小,当煤层瓦斯压力降低至安全界定值后,有效抽采区范围迅速扩张。增大抽采负压无法有效改善有效抽采区范围。抽采钻孔布置间距越小,有效抽采区的范围提升越快。最终确定芦河煤业3号煤层顺层抽采钻孔的布置参数为:钻孔直径94 mm,抽采时间50 d,抽采负压20 kPa,钻孔间距5 m。
In order to explore the influence of different extraction parameters on the gas extraction effect under bedtime extraction conditions,taking the 3#coal seam of Luhe Coal Industry as an example,the double pore medium model combined with the solid deformation equation was used as the solid field governing equation,and the Fick diffusion and Darcy's law combined with the fluid continuity equation were used as the fluid field governing equation,and the multi-field coupling numerical model of gas extraction was established by COMSOL software.The variation law of gas pressure and effective extraction area under the influence of borehole diameter,extraction time,pumping negative pressure and borehole spacing was explored.The results show that the gas extraction efficiency increases with the increase of borehole diameter.The gas pressure decreases with the increase of pumping time,and the effective extraction area of the borehole in the early stage of extraction has a small range,and the effective pumping area expands rapidly when the coal seam gas pressure decreases to the safe defined value.Increasing the negative pressure of extraction cannot effectively improve the scope of effective extraction area.The smaller the spacing of the extraction borehole arrangement,the faster the scope of the effective extraction area increases.Finally,it was determined that the layout parameters of the 3#coal seam along the bed of Luhe Coal Industry were as follows:the diameter of the borehole was 94 mm,the extraction time was 50 d,the negative pressure of the extraction was 20 kPa,and the spacing of the boreholes was 5 m.
作者
胡永军
HU Yongjun(Shanxi Lanhua Tongbao Coal Industry Co.,Ltd.,Gaoping048400,China)
出处
《煤矿现代化》
2024年第3期114-118,共5页
Coal Mine Modernization
关键词
瓦斯治理
顺层抽采
瓦斯压力
数值模拟
多场耦合
gas control
reservoir pumping
gas pressure
numerical simulation
multifield coupling
