Study On The Reasonable Hole Sealing Depth Of Gas Drainage Borehole In The Zhangji Coal Mine

The gas a serious threat to the efficient production of coal mine safety in coal mine production process,gas drainage is one of the key methods of gas control problems,the gas drainage can not only reduce the security risks,also can realize the effective use of gas,is conducive to environmental protection.The drilling and extraction method is one of the..By mainly relying on the drilling and sealing to complete pumping drilling,sealing quality has great influence on the gas drainage effect,the gas drainage hole sealing quality is poor,resulting in the drilling of gas drainage in low concentration,borehole drainage time is not long,in order to improve the gas drainage concentration and extraction efficiency,so gas drainage hole sealing is a key ring,and the sealing depth of gas drainage is the key.Through consulting a large number of references,based on the analysis of influence factors of gas drainage borehole sealing depth and borehole stress distribution,drilling in shaping and similar roadway,will be formed around the "three zones"(unloading zone,st:ress concentration zone and original stress zone).Analysis of the depth of sealing hole gas drainage borehole than coal seam pressure relief zone,into the stress concentration belt or the original stress zone.In view of the coal seam under different geological conditions,it is necessary to calculate the area of the pressure relief zone and the stress concentration zone in order to determine the reasonable sealing depth.The Zhangji mine 13-1 coal is 1123(3)statistics and calculation parameters of physical and mechanical properties of the bottom of the coal rock roadway,the application of FLAC3D software to simulate the drilling process,combined with the previous theoretical analysis is obtained and the stress concentration zone of plastic zone,for field application,and will use the different ways of sealing and sealing depth measured by gas data were analyzed,and ultimately determine the reasonable depth of sealing hole of 13-1 coal is 8?10m.