Study On Methane Controlling Technology Of Upper Protective Seam Mining Of 5121(S)B9B Working Face Of Xieyi Coal Mine

Adopt the protective layer mining technology and carry out pressure relief gas extraction, is one of the most effective measures to prevent coal and gas outburst. The mine of Huainan Mining Group as research background, in view of the mine coal and gas occurrence characteristics, choose 5121 (s) B9b coal seam as the protection layer mining and discharging pressure gas drainage, of protected layer B8 coal seam gas control technology.The mining 5121 (s) B9b used in coal seam of pressure relief gas governance as the engineering background, using rock mechanics, elastic mechanics theory of coal and rock pressure relief theory analysis, protection layer mining after the basic rules of overlying strata movement and overlying strata movement in the abscission layer and fracture and underlying petrologic fissures development rules and analysis underlying coal rock mass permeability and pressure relief gas seepage law. By using FLAC3D numerical simulation software, the stress distribution and the movement and deformation of the surrounding coal and rock mass are analyzed. Under the guidance of theoretical analysis and numerical simulation results, first 5121 (s) B9b protection layer mining and B8 coal seam pressure relief gas drainage experiment design; analyzing the protected layer B8 coal seam of the main parameters and pressure relief gas drainage effect; of mining upper protective layer 5121 (s) B9b coal seam to prevent coal and gas outburst effect was evaluated.In this paper, the range of pressure relief after protective layer was investigated, and the deformation amount of coal seam, gas drainage amount, residual gas content, and the gas desorption index and the amount of drilling debris were measured. Obtained by measured data in the field:predict 20161 month cumulative drainage protected layer B8 coal seam gas 233.86 million m3, the extraction rate was 55.1%, of which the unloading pressure gas accounted for 85.8%, be protective layer B8 coal seam measurement of residual gas content of 3.76-4.35m3/t and maximum residual gas content 4.35m3/t, B8 working face (North) to process a total of 43 coal lane tunneling, drill cuttings gas desorption index Klmax for 0.19ml/(G-minl/2), drill bits Smax 4.9kg/m. More than were less than the anti sudden provision "work face outburst prediction reference critical value. The results show that the mining and pressure relief gas extraction by 5121 (S) B9b is better in the protection layer B8 coal seam area.