Jinneng Holding Equipment Manufacturing Group Co., Ltd.

针对长平矿“三高、三多、三软、一低”的地质特征,拟采用顺层长钻孔水力造穴卸压增透技术对煤层进行改造,依托COMSOL数值模拟软件对水力造穴半径参数与抽采时间参数条件下的瓦斯压力分布状态进行分析,确定抽采参数。在3#煤层开展工业试验进行对比分析,对水力造穴出煤量与平均抽采瓦斯纯量的内在机理进行探究。结果表明:0.4m的水力造穴半径和90d的抽采时间是最优参数,对比分析未进行水力造穴卸压的Z2钻孔与进行水力造穴卸压的Z1、Z3钻孔瓦斯浓度数据表明,Z1、Z3钻孔的浓度明显低于于Z2钻孔约8%~13%;瓦斯抽采纯量与出煤量表现为先上升后下降的二次函数关系,主要受煤层非均质性影响,坚硬区域煤层的渗透性较低,限制了出煤量与瓦斯的抽采效果,松软区域煤层中钻孔易发生塌孔或蠕变变形,从而限制了瓦斯的抽采效果。

In view of the geological characteristics of "three highs, three more, three softs, and one low" in Changping Mine, it is proposed to use the bedding long borehole hydraulic acupoint creating pressure relieving and permeability enhancing technology to conduct a transform for the coal seam. With the help of COMSOL numerical simulation software, the gas pressure distribution status under the conditions of hydraulic acupoint creating radius parameters and drainage time parameters is analyzed to determine the drainage parameters. Comparative analysis is conducted on industrial experiments in the 3# coal seam to explore the inherent mechanism between the coal output from hydraulic acupoint creating and the average gas drainage scalar quantity. The results show that a hydraulic acupoint creating radius of 0.4 m and a drainage time of 90 days are the optimal parameters. The comparative analysis of the gas concentration data between the Z2 borehole without hydraulic acupoint creating pressure relief and the Z1 and Z3 boreholes with hydraulic acupoint creating pressure relief shows that the concentration of Z1 and Z3 boreholes is significantly lower than that of Z2 borehole by about 8%-13%; The gas drainage scalar quantity and coal output show a quadratic function relationship of first increasing and then decreasing, mainly affected by the heterogeneity of coal seams. The permeability of coal seams in hard areas is low, which limits the coal output and gas drainage effect. In soft areas, boreholes in coal seams are prone to collapse or creep deformation, thereby limiting the effect of gas drainage.