One-roadway dual-purpose gas extraction method for high-position roadway of fully-mechanized caving coal seam

Abstract

The invention discloses a one-roadway dual-purpose gas extraction method for a high-position roadway of a fully-mechanized caving coal seam, and belongs to the technical field of gas extraction, which can solve the problem of gas overrun of a fully-mechanized caving face of a high-gas low-permeability thick coal seam. Before the fully-mechanized caving face of the high-gas low-permeability thick coal seam adopting a U-shaped ventilation mode is extracted, the high-position roadway of the coal seam is constructed along a top plate of the coal seam in an inner staggered working face air return roadway, high-position coal seam drill holes are constructed in the high-position roadway of the coal seam from a non-coal pillar side to an air inlet roadway, and the high-position coal seam drill holes are connected with a mine gas extraction system for extraction. When the working face is extracted, all the high-position coal seam drill holes are disconnected from the extraction system and are in an open natural gas discharging state, and additionally, closed insertion pipe extraction is constructed at the opening of the high-position roadway of the coal seam. According to the method, one roadway has two purposes, and the gas extraction method has the characteristics of investment saving, easiness in management, high gas extraction rate and the like.

Description

technical field [0001] The invention belongs to the technical field of gas drainage, and in particular relates to a gas drainage method for a fully mechanized caving face, in particular to a gas drainage method for fully mechanized caving mining in a single low-permeability thick coal seam. Background technique [0002] While the fully mechanized top coal caving technology has the advantages of high production and high efficiency, it also has the advantages of large absolute gas emission, local gas accumulation in the upper corner, large unbalanced gas emission coefficient, and instantaneous gas emission in the goaf in terms of mine gas prevention and control. Disadvantages such as large area gush. It poses a great threat to the safe production of coal mines. [0003] At present, the gas control technology of fully mechanized caving mining generally adopts the pre-pumping of gas in the coal seam before mining, the use of pre-pumping boreholes to drain the coal seam pressure...

AI Technical Summary

Problems solved by technology

When the thick coal seam is pre-extracted before the mining of the working face, the ordinary bedding boreholes cannot be evenly arranged, and there are blank areas for gas drainage; the kilometer-long directional drilling can solve the problem that the ordinary bedding boreholes cannot be evenly arranged, but its The requirements for coal seam geological occurrence conditions are relatively high, and the extraction effect is poor in coal seams with developed structures and mudstone interbeds

During the recovery of the working face, the kilometer directional drilling is easily affected by the advanced support pressure, and it may be completely cut off in the part with poor geological conditions, and cannot play the role of pressure relief gas drainage; at the same time, the high drainage roadway is generally arranged in the fracture zone , the distance from the coal seam is far away, it can only act on the deep part of the goaf, and cannot effectively solve the problem of gas exceeding the limit in the upper corner

Images