Study On Application Of Comprehensive Gas Control Technology In Driving Face Of Guanyinshan Mine

Aiming at the problems of difficult permeability enhancement and low gas drainage efficiency in strong outburst coal seam,taking w1101 working face of Guanyinshan coal mine as the engineering background,the combination of theoretical analysis,numerical simulation and field practice is used to systematically study and apply the hydraulic reaming and permeability enhancement mechanism,supporting equipment,"long pumping and short drainage" technology and evaluation method in strong outburst coal seam.The results are as follows:(1)The effect of gas control measures in coal roadway excavation is analyzed,and the problems of gas control in coal roadway excavation are summarized,which are mainly caused by poor permeability of coal seam,unreasonable floor roadway position,drilling field and drilling design and construction,hole collapse caused by poor floor lithology and poor hole forming effect of long drilling along the layer,then the gas control measures need to be improved.(2)The basic characteristics of high-pressure water jet reaming,the impact process of water jet and the redistribution law of coal stress after reaming are theoretically analyzed,and the coal breaking mechanism of high-pressure water jet is revealed;The reaming equipment is preferred,the emulsion pump is preferred to be BRW200 / 31.5,the ejector is preferred to be FTZKQ1-50-P40,the reaming drill pipe is preferred to be FTZKG1-50-P40,and the rotating water tail is preferred to be FTZKW1-50-P40.(3)Based on theoretical analysis and engineering experience,the reasonable range of hydraulic reaming pressure is determined to be 8 ? 15 MPa,and the mathematical calculation model of hydraulic reaming chip removal is established;FLAC3D is used to reveal the evolution law of stress and displacement of coal in boreholes with different diameters,and the half diameter of reaming is finally determined to be 0.5m.(4)The construction layout parameters of hydraulic reaming,drilling yard,long pumping hole and short row hole are designed,and the hole sealing process was determined as bag polyurethane two-stage hole sealing;Local hydraulic reaming + the "three indicators" technology system of " long extraction and short drainage " gas control have been implemented,and good application effect has been achieved,the frequency of gas exceeding the limit of 100 meters in coal roadway excavation has been reduced by 86%,and the gas exceeding accidents with concentration above 1.5%have been eliminated.The driving efficiency of coal roadway increased significantly,with the monthly driving footage increasing from 41.9m to 73 m,with an increase of74%.The maximum driving footage of coal roadway was 86 m,with an increase of105%.This article has 54 figures,16 tables,96 references.