Technical Research On 1000m Deep Shaft Uncovering The Coal Seam In Huaan Coal Co.,ltd.

TheⅡ1 coal seam of main shaft in Henan Huaan Coal Co.,Ltd. exists in 929 m deep. So in order to uncover coal seam safely, this paper aimes at this special case has done a lot of work at predicting the dangerous of coal seams quickly and eliminating the danger of outburst well.On the prediction of the danger of outburst, through studying the measure of gas pressure, I obtain that by high pressure grouting with “double capsule--mucus sealing hole” method can realize the rapid and accurate determination of gas pressure. The gas pressure of Ⅱ1 coal seam is 3.3MPa. In the determination of gas content, the sampling method is that compressed air blow coal samples quickly, the measured gas content is 16.85m3/t. In addition, the outburst danger prediction index: the initial release gas expansion energy is added, and the number is 184.8m J/g. Through the determination of three indexes of main shaft, we think Ⅱ1 coal seam has the strong danger of outburst.Because high stress affects the permeability coefficient of coal seam, and then affects the outburst elimination and its efficiency. In order to eliminate danger, we need take measures. Through the study on the partition of coal around the borehole find that, improving the drilling diameter can greatly improve the coal seam permeability coefficient, so that we can realize the pressure relief and permeability increase. Under the same condition, the effective pumping radius of the coal seam gas can be increased effectively by increasing the borehole diameter. Therefore, in the construction of dense boreholes, hydraulic reaming as an auxiliary measure is used at the same time, in order to expand the borehole radius. Then in order to achieve the cycle purging hole operation later, the method of borehole sealing with casing of the length of 3m, diameter 108 mm in orifice section is chosen, and connecting the drainage pipe with flange way. This method not only can achieve the repair of drill holes and can remove the water in drill holes, so we can realize gas drainage smoothly. Through the statistical data of the latter part of the gas drainage volume proves that the elimination measures are effective.