Research On Regional Outburst Prevention Technology For Pre-draining Gas In Layered Drilling In Tucheng Mine

Coal is the main source of energy in China,coal mine enterprises have also begun to pay more and more attention to the management of coal mine gas.For coal seam gas,pre pumping is an important measure to control the gas disaster in the coal mine area.The 13163 working face of Tucheng coal mine is used to drill long holes in the transportation lane.The danger of eliminating gas outburst in the area is eliminated.As a background,this paper analyzes the law of gas migration and the distribution of flow field around the gas extraction boreholes,providing effective guidance for the design and construction of mine gas extraction drilling and the prevention and control of the area.The following conclusions are obtained:(1)Gas extraction makes the gas in the coal seam gradually appear analysis,diffusion and flow state.According to the flow state of gas in the space,the gas flow field is divided into one direction flow field,radial flow field and spherical flow field.The main gas flow in the seam bedding borehole is radial flow.(2)The gas flow around a single paramedic extraction borehole presents a radial flow state.With the increase of extraction time,the gas pressure around the drilling hole is continuously reduced.The diameter of the drilling hole,the gas pressure of the coal seam and the pumping pressure are the factors affecting the drilling of the borehole,and the diameter of the drilling hole is 50 mm and the suction pressure is 15 k Pa.In order to reach the effect of gas extraction,the gas is radial flow,the bottom of the borehole presents the state of ball pumping,and the long drilling range of the CIS layer can expand 10 m from the bottom of the borehole to the outside of the coal seam.(3)The gas pressure in the middle part of the coal seam is effectively extracted and the gas pressure is continuously reduced.The gas pressure is still in a high state on both sides of the coal seam because of the supplementary effect of gas in the far field.The interlayer gas extraction spacing is the main factor affecting the gas extraction time.Reducing the distance between the CIS drilling holes can effectively reduce the extraction time,and the reasonable drilling spacing should be selected according to the time of the concrete excavation replacement.(4)The 13163 working face of Tucheng coal mine uses the long bore hole drilling as a regional outburst prevention measure in the original stress zone,driving the 13163 lane as a bedding drilling hole,adopting the full section first entry method,and adopting the anchor net support technology.In the transportation lane,each 8m along the 16# coal seam tends to construct a cis-layer long hole,the design of17-degree angle,the depth of 160 m,the design of drilling can effectively increase the effect of gas extraction.