Method and device for constructing bedding gas extraction long drilled holes of soft coal seams

Abstract

The invention discloses a method and a device for constricting bedding gas extraction long drilled holes of soft coal seams. The method and the device are applied to drilling the bedding gas extraction long drilled holes of the soft coal seams, and are characterized in that two types of gas-based fluid including compressed air and stable foams are used as drilled hole washing media, are alternately injected into a drilled hole, reach the bottom of the hole, then flow into annular clearance via flow channels in a drill bit, cool the drill bit and carry coal cinder dust which is generated along with drilling actions of the drill bit at the bottom of the hole, then the drilled hole washing media and the coal cinder dust return the outside of the hole, stable foam flow carries the coal cinder dust, and cools and lubricates drilling tools, and compressed air flow washes the bottom of the hole and pushes stable foam slug to flow. The method and the device have the advantages that the cinder discharge capacity is high, a drilling tool cooling effect is good, orifices are free of dust pollution, the rotation pressure of a drilling machine can be obviously reduced while the drilling capacity of the drilling machine is improved, and the drilling machine can normally drill holes in water-containing coal seams; the flow rates of gas and liquid are regulated under the control of special valve blocks by the aid of the method and the device, the device can be operated easily and conveniently, is small in size and is light, the method and the device are applicable to underground drilling construction operation environments of coal mines, and the like.

Description

technical field [0001] The invention relates to a long drilling method and device for bedding gas drainage in soft coal seams, in particular to a long drill hole for gas drainage in soft coal seams using compressed air and stable foam as the drilling flushing medium in a compound manner. Hole method and device. Background technique [0002] my country's soft coal seams are widely distributed, accounting for a considerable proportion of mineable coal seams. Gas disaster control is particularly important in the process of mining soft coal seams. It is a key factor affecting the popularization and application of high-yield and high-efficiency coal mining technology, and it is also one of the problems that plague the increase in production. Gas pre-drainage is the most effective technical means to reduce gas content in soft coal seams and prevent gas disasters, and it is also the basis for comprehensive utilization of gas. The key to underground gas pre-drainage in coal mines ...

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Problems solved by technology

[0006] The technical problem to be solved by the present invention is: for the poor cooling capacity of pure air and the hidden danger of gas explosion in the hole when using the medium-wind pressure air drilling technology to construct the long boreholes for gas drainage in soft coal seams in coal mines, and meet the slag discharge requirements. The required annular air flow rate is high, which is unfavorable for the stability of the hole wall in the soft coal seam. It is difficult to discharge slag after drilling into the water-bearing coal seam, and it is easy to cause drill stuck accidents in the hole. It provides a long drilling construction for gas drainage in the soft coal seam Method and device

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