Gas treatment method for underground coal mine soft outburst coal seam having large-mining-length working face

Abstract

The invention provides a gas treatment method for an underground coal mine soft outburst coal seam having a large-mining-length working face. The gas treatment method comprises the following steps that step I, a directional drilling machine drills holes in a coal seam roof or floor rock extraction roadway; step II, after directional layer-crossing hole-drilling construction in the step I is performed on a coal seam, hole drilling is performed until the hole drilling construction is performed on a designated position; step III, after the hole drilling in the step II is constructed in place according to a hole drilling track, hydraulic hole punching and coal unloading operations are performed; step IV, a conventional rotary drilling tool in the drilled hole is withdrawn, and networking negative pressure extraction is performed on a sealed hole; step V, in the extraction process, according to the monitoring result of a regional gas extraction on-line monitoring and metering device in thestep IV, a secondary hydraulic hole through operation is performed on drilled holes of which the single-hole gas extraction concentration is lower than 10% for coal seam permeability improvement, andthen networking extraction is performed anew step VI, according to the metering result of the regional gas extraction on-line monitoring metering device in the step V, the advantages of the directional drilling machine and the advantages of a conventional rotary drilling machine are brought into full play through a drilling mode of combining a directional drilling machine technology and a conventional rotary drilling technology. The problems that during construction of a conventional rotary drilling machine, drilled holes are easily subjected to hole communication, and a drill rod is not proneto enter a coal seam due to self-weight influence are effectively solved.

Description

technical field [0001] The invention relates to the technical field of controlling gas in outburst coal seams in underground coal mines, in particular to a method for controlling gas in soft and outburst coal seams in large mining long working faces in underground coal mines. Background technique [0002] For the gas control of the single coal seam recovery working face in the coal mine, the purpose of coal seam gas control in the working face is generally achieved by drilling holes into the coal seam and pre-extracting the coal seam gas. Drilling holes for pre-extraction of coal seam gas include two types of drilling along the coal seam and drilling through the seam from the gas extraction roadway. Due to the problems of unclear drilling trajectory and final hole position, easy hole collapse, and low drilling hole formation rate during the bedding construction of this coal seam, the drilling is not deep, and it is easy to leave a blank zone for extraction. Therefore, some l...

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Problems solved by technology

[0005] The present invention aims to solve the problem that the gas control project of the long working face in the prior art is huge, the cost is high, and the cycle is long, and the balance of "pumping, mining and excavation" of the mine is not used and the problem of affecting the normal replacement of the working face is solved. For the above problems, the present invention provides a gas control method for soft and protruding coal seams in large mining length working faces in underground coal mines

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