Reverse Drilling Construction Method of Fresh Air Well in High Gas and Outburst Coal Seams

Abstract

The invention relates to a reverse drilling construction method of a high-gas and outburst-coal-seam fresh air shaft, and belongs to the field of coal mine fresh air shaft construction. The reverse drilling construction method of the high-gas and outburst-coal-seam fresh air shaft comprises the steps of constructing a bearing platform on the earth surface of a fresh air shaft, and arranging a drilling platform; connecting a drill rod with a construction drill bit with a propelling system, a water tail and a pump station; starting drilling from the earth surface, passing through a rock stratum,and penetrating through a coal seam until arriving at a concentrated air return way under a coal mine; unloading the construction drill bit; lowering the drill rod into the concentrated air return way under the coal mine, and connecting with the tapered drill bit; drilling toward the earth surface from the concentrated air return way under the coal mine, lowering the drill rod with the tapered drill bit into the concentrated air return way under the coal mine, unloading the tapered drill bit, and connecting a construction platform with the drill rod; applying a drilling machine to construct gas extraction drilling in the coal seam, connecting the tapered drill bit with the drill rod after the coal seam gas content reaches to an allowable exposed threshold value, and perpendicularly drilling toward the direction of the earth surface until arriving at the earth surface. After a fresh air shaft body is formed, spouting and reinforcing are carried out on the inner part of the fresh air shaft from the underground coal mine to the earth surface.

Description

technical field [0001] The invention belongs to the field of construction of fresh air shafts in coal mines, and relates to a reverse drilling construction method for fresh air shafts in high gas and outburst coal seams. Background technique [0002] Coal mine gas is an unconventional natural gas that is associated with coal and is mainly stored in coal seams in an adsorbed state. Its main component is methane, and a small amount of ethane, propane and butane. And water vapor, and trace amounts of inert gases, such as helium and argon. Gas is the main threat to mine safety production, especially during shaft construction, if coal and gas outburst or abnormal gas gushing occurs, it is very easy to cause accidents of "mass death and mass injury" of operators. At the same time, with the development of current coal mining and safety technology, the output of many original high gas or coal and gas outburst mines is gradually increasing, and the construction of new air shafts to ...

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Problems solved by technology

[0004] In view of this, the object of the present invention is to provide a reverse drilling construction method for new air wells in high gas and outburst coal seams, which solves the problem of downhill drilling when exposing high gas or coal and gas outburst coal seams in the traditional air well construction process. The problem of poor gas drainage effect by drilling through layers can greatly reduce the construction period of fresh air wells, and can also effectively prevent casualties caused by disasters

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