Technology Study On The Hydraulic Flushing With Improving Permeability And Relieving Pressure

In this paper, based on the conditions of large changes in coal thickness,coal soft,poor ventilation,and no protective layer of coal mining to Xinan Yian mine for the experiment, the theoretical analysis, field test study and numerical simulation methods, to carry out unloading hydraulic flushing pressure Outburst key technology areas. The amount ultimately improve drainage, reduce the quantities of measures in order to reduce the time and the achievement of security measures to quickly remove Outburst purposes. In the high-pressure water jet Bottom Road, hydraulic flushing use the highlight risk of the of coal as a safety barrier of rock, out of a large number of coal and exclude certain amount of gas. Allows the release of coal gas potential; then closed pre-pumping coal seam gas drilling to further reduce the coal seam gas pressure and gas content, while coal seam can cause deformation, stress drop, and increase of gas permeability changes, to weaken until the purpose of eliminating outburst. In order to investigate measures to eliminate sudden hydraulic flushing effect, and to determine reasonable and effective radius of influence. This paper studies the content as follows:â‘ the use of theory to water damage and failure process of punching broken coal is divided into three periods: crack, water wedge effect, the role of coal broken. Also analyzed at different periods, for which coal and rock strength criterion.â‘¡by Ngee Ann Mine site visit test against outburst of hydraulic punching, punching through to change water pressure, nozzle type and other punching equipment, use of flow and pressure effects were investigated by the effective radius of punching in between 6.5 ~ 8m .â‘¢combination of numerical simulation software RFPA vertical pressure in certain circumstances, relief punching holes within the scope of the relationship between size and pressure relief, and the holes around the stress of coal, coal displacement, changes in gas flow and gas variation of pressure gradient, while simulated two different holes in the pressure relief aperture range of changes.â‘£hydraulic punching in the implementation of measures completed in the right place cloth Bottom Road.