Top plate high-position boring large-diameter long-drill-hole gas extraction method based on directional drilling

Abstract

The invention particularly relates to a top plate high-position boring large-diameter long-drill-hole gas extraction method based on directional drilling. The method solves the problems of great engineering quantity of the existing high-drainage roadway extraction and poor extraction effect of ordinary drill high-position hole drilling. The method comprises the following steps that: a, a plurality of drill sites are constructed at intervals at a ventilation connection roadway of an extraction working face, and drill holes constructed in the two adjacent drill sites are in lap joint; b, four drill holes are totally constructed in each drill site, and each drill hole passes through a working face crossheading position part and is positioned above a top plate; c, before the drill hole construction, a hole opening pipe is installed, and a hole opening gas-liquid separator is connected; d, rotary drilling is performed in a hole forming section, then, a hole sealing pipe is put at a hole sealing section, and a drilling machine directionally drills to a terminal hole and performs whole-process hole reaming after the grouting hole sealing; e, the outer end of the hole sealing pipe is connected with a snake-shaped pipe through a flange, and the other end of the snake-shaped pipe is connected with a gas collecting opening of a drainage pipe; and f, when a working face is pushed to a position passing through the hole bottom of a drill hole, the drainage operation is carried out. The top plate high-position boring large-diameter long-drill-hole gas extraction method improves the mine gas extraction rate, and has the advantages that the extraction concentration is high, and the flow rate is great.

Description

technical field [0001] The invention relates to an underground coal mine borehole gas drainage method, in particular to a directional drilling-based method for gas drainage of a large-diameter long borehole with a high position on the roof. Background technique [0002] At present, the vast majority of coal mines are high-gas or coal and gas outburst mines. With the increase of mining depth and the improvement of mechanization level, the gas gushing out of gobs will become increasingly serious, especially in low-permeability coal seam areas. It will become the main means to reduce the gas gushing out of the mining face. [0003] Gas drainage in the goaf mainly adopts drilling drainage, roadway drainage, and buried (insertion) pipe drainage. The roadway drainage method has greatly increased the amount of rock tunneling in the mine; the buried (inserted) pipe drainage method can only solve the gas accumulation in the goaf, but cannot drain the gas in the fissure zone of the g...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem that the existing high-level gas drainage has a large amount of work and the general drilling high-level drilling effect is poor, the present invention provides a gas drainage method based on directional drilling with a large diameter and a long hole in the high position of the roof. method