Front-injection back-extraction parallel coal seam inclined drilling gas control device and method

Abstract

The invention provides a front-injection back-extraction parallel coal seam inclined drilling gas control device and method. The device comprises double hole sealing pipes, an air bag, a plastic pipeline, a sponge body, a clamp hoop, an inflating device, a grouting pipe, a fixed retainer ring and a sliding device; one hole reaches dual purposes; the front end is used for gas displacement through water injection, and the back end is used for gas extraction through negative pressure; through a blade-shaped iron sheet arranged on the inner wall of an inner pipe and a front-dense and back-sparse sponge body which is arranged at the front half part of a pressure relieving region and can be expended after meeting water, the problem of water injection nonuniformity due to broken degree of the loose coal body of the front half part of the pressure relieving region is solved; and excessive water solution can be prevented from flowing out from big pores of loose coal bodies. By using the front-injection back-extraction method, the air leakage from the pores and cracks of the loose coal bodies can be prevented; the coal seam gas extraction efficiency is improved; free gas of the loose coal body can be effectively expelled; the desorption of adsorption gas can be inhibited; and the gas gushing quantity during the working face stoping is reduced.

Description

technical field [0001] The invention relates to the field of gas control in inclined boreholes along coal seams, in particular to a device and method for controlling gas in inclined boreholes along coal seams with water injection at the front end to drive free gas and prepare adsorption gas desorption, injecting at the front and pumping after pumping. Background technique [0002] As we all know, drainage is a fundamental measure to prevent and control gas. The inclined drilling along the coal seam refers to the drilling from the roadway to the working face, and the drilling axis is oblique to the roadway axis. figure 1 shown. [0003] Due to the effect of mine pressure, there is a certain pressure relief area at the edge of the coal seam adjacent to the roadway and working face; figure 2 shown. [0004] The part of the inclined borehole along the coal seam in the pressure relief area at the edge of the roadway, that is, the rear end of the borehole, has been filled with...

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Problems solved by technology

[0006] To sum up, the inclined drilling along the coal seam can use the second half of the coal seam pressure relief area at the edge of the working face to improve the gas drainage effect, but the existence of the front half of the area will in turn reduce the gas drainage effect

[0007] At present, the research on gas drainage mainly focuses on the research and development of sealing materials, the layout of drainage boreholes and the extraction time, etc. However, there is no relevant information about the air leakage at the front end of the inclined drilling along the coal seam in the open literature. Research results

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