Research And Application Of Gas Drainage Technology Of Long Bedding Boreholes In Fracture Zone Of Shuguang Coal Mine

Shuguang Coal Mine of Shanxi Fenxi Mining(Group)Co.,Ltd.adopts the measures of high level drilling in the construction of high level drilling field to extract the goaf gas to prevent and control the gas.Due to the existing general drilling depth,uncontrollable trajectory,the number of drilling field,low rig monthly efficiency and other factors,under the environment of the depressed coal economic situation,How to reduce cost and increase efficiency and mining safely has become a difficult problem restricting gas control in Shuguang Coal Mine.In order to further improve the effect of gas drainage from mined-out fractured zone,reduce the cost of gas treatment and ensure the safety of mining face,Shuguang Coal Mine introduced the large-diameter roof directional long drilling technology to drain gas from the overburden rock fractured zone of working face,and studied and determined the layout and construction technology of high-position directional drilling.The field industrial tests show that the vertical directional boreholes are arranged in the gas accumulation area in the middle and lower part of the fracture zone 17.1 ～ 22.8m above the roof.In the horizontal direction,the distribution range of drilling holes is 15 ～ 35 m away from the return air roadway,and the spacing of drilling holes is 10 m.Compared with the common high-position drilling drainage technology,this technology not only significantly reduces the number of high-position drilling field and drilling footage,significantly shortens the construction period and reduces the construction cost,but also significantly superior to the conventional drilling technology.The average single hole gas drainage volume increases from 0.15m3/min to 1.55m3/min,an increase of 9 times.The extraction life of borehole was increased from 18～33d to more than146 d,which was increased by more than 4 times.The use of large diameter directional long drilling technology in fractured zone can significantly improve the gas treatment effect and reduce the treatment cost,which has a wide range of application value.