1.Henan Provincial Key Lab of Gas Geology and Gas Control,Cultivation Base,Province and Ministry Joint State Key Lab,Henan Polytechnic University, Jiaozuo ,China;2.State and Local Joint Engineering Lab of Gas Drainage and Surrounding Rock Control Technology in Deep Coal Mine,Henan Polytechnic University,Jiaozuo ,China;3.School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo ,China; 4.Henan Provincial Collaborative Innovation Center of Safety Coal Production,Jiaozuo ,China

为了揭示多物理场耦合作用下本煤层顺层钻孔瓦斯抽采渗流机制,建立了考虑Klinkenberg效应、有效应力和解吸收缩影响的流固耦合模型,运用该模型对本煤层顺层钻孔抽采参数进行优化。结果表明:抽采时间对有效抽采半径影响非常显著,钻孔抽采1 d时有效抽采半径为0.38 m,钻孔抽采10 d时有效抽采半径的范围仅增加1.55倍,抽采180 d时有效抽采半径的范围增加8.26倍;在高瓦斯压力区域,煤层钻孔周围煤体的孔隙率、渗透率呈现下降趋势,随着钻孔抽采影响程度的减小,煤基质解吸收缩效应逐渐加强,孔隙率、渗透率下降趋势逐渐缓慢,模拟结果与理论分析相吻合;随着抽采钻孔直径的增加,钻孔周围煤体的瓦斯压力降低范围逐渐增大,有效抽采半径与钻孔直径之间满足幂函数关系,在保证钻孔抽采效果的前提下,确定某矿29031工作面最合理的钻孔直径为94 mm。

In order to reveal the gas drainage seepage mechanism of the borehole drilled along the mining seam under the coupling effect of the multi physical field,a fluid-solid coupling model with a consideration of the Klinkenberg effect,the effective stress and the desorption shrinkage influence was established. The model was applied to optimize the drainage parameters of the borehole drilled along the seam. The results showed that the drainage time would be very effected to the effective drainage radius. When the drainage time was a day,the effective drainage radius would be 0.38 m. When a drainage time of the borehole was 10 days,the effective drainage radius would be increased by 1.55 times only. When the drainage time was 180 days,the effective drainage radius would be increased by 8.26 times. When in the high gas pressure area,the porosity and permeability of the coal around the borehole in the seam were in a decreasing tendency. With an influence degree of the borehole gas drainage decreased,the desorption and shrinkage effect of the coal matrix would be steadily improved,the declining tendency of the porosity and permeability would steadily be slow and the simulation results and the theoretical analysis would be well consistent. With the diameter of the gas drainage borehole increased,the gas pressure reduced scope in the seam around the borehole would be steadily increased and the effective drainage radius and the borehole diameter could meet the power function relation. Under the prerequisite to ensure the gas drainage effect of the borehole,the most rational borehole diameter determined in No. 29031 coal mining face of a mine was 94 mm.

国家自然科学基金青年科学基金资助项目(51604101；51734007)；河南理工大学博士基金资助项目(B2018-59)；河南省瓦斯地质与瓦斯治理重点实验室——省部共建国家重点实验室培育基地开放基金资助项目(WS2017B06)；深井瓦斯抽采与围岩控制技术国家地方联合工程实验室开放基金资助项目(G201608)；