A method for pre-pumping and preventing outburst of strong outburst coal seam

Abstract

The invention discloses a pre-drainage outburst prevention method of a strong outburst coal seam. A definite high gas coal seam mine area exists. The method comprises the following steps: firstly drilling two shafts in the inner edge of the mine area along the trend of a roadway to be excavated and cementing by using cement from a part which is one meter away from the coal seam to the side wall of a wellhead; reaming the coal seam by using a high-pressure water injection reaming process; then performing fracture gas gap penetration between two reamed coal seam holes by using an aerodynamic cavity forming process; drilling a third shaft in the mine area within a range which is at least 60 meters away from the two shafts, communicating with the first and second shafts by using a transverse drilling mode respectively after the third shaft enters the coal seam, sealing the wellhead of the third shaft, and draining gas from the first and second shafts until the gas concentration is less than a standard value. According to the method, a passage from the ground to an underground roadway coal uncovering area is established by using the two shafts and the multi-branch horizontal well in the ground, so that more coal can be taken out, more gas can be drained, and the gas content and pressure in a target coal seam are greatly reduced to achieve the outburst prevention purpose.

Description

technical field [0001] The invention relates to the field of coal mine safety, in particular to a method for pre-pumping and preventing outburst of strong outburst coal seams, and is a method for preventing gas outburst accidents in which deep gas outbursts strongly out of coal seams. Background technique [0002] At present, mines that have safety risks for underground stone gates or coal mines in roadways, such as coal mines that are being mined, detect a high gas area at a certain distance from the mining roadway. In order to eliminate the high pressure and high gas in the mining area to be mined, now The method of gas pre-extraction in downhole drilling is generally adopted. This method has the problems of large drilling engineering, difficult construction, high cost investment, long extraction time, affecting normal production planning, and the possibility of gas outburst and gas overrun accidents in the hole during the drilling process. Especially for mines that are d...

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Problems solved by technology

This method has the problems of large drilling engineering, difficult construction, high cost investment, long extraction time, affecting normal production planning, and the possibility of gas outburst and gas overrun accidents in the hole during the drilling process

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