Dredging and re-extraction method for coal seam gas extraction borehole collapse

Abstract

The invention belongs to the field of coal mine safety, and relates to a dredging and re-extraction method for coal seam gas extraction borehole collapse. The dredging and re-extraction method comprises the steps that if the coal seam is a soft coal seam, a gear conveying device is started to convey a threaded outer rod with a soft coal seam cutting part to the collapse position, and high-pressureair in the threaded outer rod drives rotating blades to rotate, so that an ellipsoid drill bit is driven to rotate to penetrate through a collapsed coal body; if the coal seam is a hard coal seam, arubber pipe with a pneumatic motor and of a hard coal drill bit is conveyed to the collapse position, enters the air inlet end of the pneumatic motor through a high-pressure air conveying pipe, and then the rotating blades are driven to rotate, so that a rotating shaft rotates and drives the hard coal drill bit to rotate to cut a coal body at the collapse position; after the coal body at the collapse position of the gas extraction drill hole penetrates through, the corresponding device can be withdrawn immediately; and the coal body at the collapse position is penetrated through through a special drilling process, the extraction attribute of the drill hole is recovered, the gas extraction efficiency of a mine is powerfully guaranteed, and gas accidents are practically prevented.

Description

technical field [0001] The invention belongs to the field of coal mine safety, and relates to a dredging and re-drainage method for coal seam gas drainage borehole collapse. 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 safe production in mines. At present, my country mainly adopts the methods of ground drilling drainage and underground gas extraction in coal mines to control mine gas disasters. In the process of using underground gas drainage in coal mines to implement mine gas disaster control, it is necessary to use drilling rigs in coal mines to drill holes for gas drainage in coal seams. Therefore, it often leads to the phenomenon that the borehole collapses after the cons...

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Problems solved by technology

[0004] In view of this, the present invention provides a coal seam gas drainage drill in order to solve the problem that after the construction of the underground gas drainage borehole in the coal mine is completed, the gas drainage borehole fails due to collapse and blockage of the borehole, which leads to gas accidents.

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