Research On Gas Drainage Technology Of Ⅱ₁ Coal Seam In Baiping Coal Mine

Gas control is an important guarantee of coal mine safety production.Pre-drainage of coal seam gas is an important control measure to solve the mine gas disaster and realize safety production.At present,there are many technical problems in coal seam gas extraction,which needs further research and solution.The paper selected the 13031 working face of Baiping Coal Mine of Zhengzhou Coal Group as the test site.The coal seam of working face has poor permeability,large gas content,uneven occurrence,and difficult gas extraction,which brings great hidden dangers to mine safety production.The coal seam of this working face has poor permeability,large gas content,uneven occurrence and difficult gas drainage,which brings great hidden danger to the safe production of the mine.In order to solve the problem of gas extraction difficulties and the inadequate extraction technology,which caused the gas concentration in the working face to exceed the limit,the paper takes the existing extraction technology as the research content,and analyzes the bore diameter,punching/slit,sealing,and optimizing technical measures such as hole collapse/hole plugging,negative pressure of extraction,extraction time and other factors.They have influenced the gas extraction effect,such as small diameter hole formation,simple capsule sealing,borehole repair and low negative pressure extraction.In view of the uneven distribution of gas in the coal seam of the working face,the paper adopts the design scheme of densely distributed holes,respectively arranging 5 groups of normal drainage boreholes and 4 groups of optimized drainage boreholes,comparing and observing the normal and optimized drainage gas concentration 3.Trends of flow rate and statistical analysis of data.By analyzing the change trend of concentration and flow rate,it is found that the gas concentration and flow rate decrease rapidly,approximately linearly in the early stage of gas drainage.The gas concentration and flow rate increase and decrease repeatedly,showing a wavy change in the middle stage of gas drainage.In the later stage of drainage,the gas concentration and flow attenuation gradually stabilized and approximated a gentle curve,with no major changes.The research shows that with optimized technical measures,the reasonable extraction time is shortened from 6 months to 3 months,and the extraction negative pressure is reduced from 21-39KPa to 5-13KPa,and the average gas concentration is increased from 9.44%to 12.21%,and single-hole pumping volume was increased from 68.54m3 to 92.82m3,which achieved the expected pumping effect,reduced the cost of mine outburst prevention,and had significant economic benefits.The research results can be applied to Baiping Coal Mine and it also be applied in other mines with similar gas geological conditions..