| The one of the main technical means of coal mine gas control in our country is the drilling hole after embedding extraction tube, but the drilling hole sealing quality is poor,the result is that the gas extraction concentration is low,drilling effective time is short.In order to improve the drilling hole sealing quality,having developed the integration of hole sealing device and studied its sealing hole parameters.Firstly, in this paper, taking the theoretical analysis of the surrounding rock stress distribution of coal mine drilling, and combining the numerical simulation software Flac3d to simulate the stress distribution of surrounding rock drilling, obtaining from the drilling center to the outside can be divided into four areas, the broken zone-, plastic zone> elastic zone and the original rock stress zone,the broken zone has important effect on borehole seal.Secondly, based on the analysis of the best depth of drilling hole sealing, using Flac3d to simulate the best hole sealing depth in the coal (rock) body under the influence of mining, concluding that in the coal seam bedding, the drilling hole sealing depth is10-27m, while in the Layer-Through Borehole, the drilling hole sealing depth is11-19m distance from roof of the drainage lanebottom.Thirdly, with the drilling micro fissure sealing requirement, the integration of hole sealing device using pressure sealing, its advantage is to use pressure drive to promote slurry infiltration to the borehole wall rock fractures, thus improving the effect of borehole sealing.Using UDEC numerical simulation software analyzy the different coal and rock under the conditions of different drilling grouting pressure, making the grout diffusion range size, so to determine the optimal grouting pressure, concluding that coal seam drilling grouting pressure is0.6Mpa, rock drilling grouting pressure is1.4Mpa.Finally, after the theory combined with numerical simulation of the integration hole sealing device, getting hole sealing parameters, through the coal mine field test, in the process of practical application achieving better hole sealing effect.Compared with the traditional hole sealing process, this hole sealing method is more scientific and more reasonable.But,hole sealing device application in different sites have different extraction effects, through this phenomenon, the author analyzes the extraction point of geology carefully, finding that the application effects of hole sealing device are influenced by geological greatly.From the overall situation, the hole sealing device has certain advantages. |
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