Research on Hydraulic Acupoint Creating Pressure Relieving and Permeability Enhancing Gas Drainage Technology for Bedding Long Borehole
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.
bedding long boreholecoal seam permeability enhancementhydraulic acupoint creatinggas drainage
万方数据
维普
