Gas drainage borehole arrangement method for extra-thick coal seam

Abstract

The invention discloses a gas drainage borehole arrangement method for an extra-thick coal seam. The method comprises the specific steps that step 1, first drill fields and second drill fields are separately arranged toward a working area on the side of an intake airflow roadway and the side of a return airflow roadway, the first drill fields and the second drill fields are arranged alternately, and the distance between the adjacent first or second drill fields on the same side is 100m-500m; step 2, gas drainage boreholes are constructed in each first or second drill field, each gas drainage borehole includes a main hole channel and a plurality of branch hole channels distributed on both sides of the main hole channel, and the gas drainage boreholes are arranged parallel to the coal seam;and step 3, the main hole channels are subjected to hole sealing treatment and connected to a gas drainage system. Two rows of gas drainage boreholes are constructed in the intake airflow roadway andthe return airflow roadway, and the control area of the gas drainage boreholes is increased. Each borehole consists of a main hole and a plurality of branch holes distributed on both sides of the mainhole, the number of borehole sealing is reduced, and the risk of the poor gas treating effect due to the hole sealing problem is reduced.

Description

Technical field: [0001] The invention relates to the technical field of mine gas control and utilization, in particular to a method for arranging drilling holes for gas drainage in extra-thick coal seams. Background technique: [0002] my country is the world's largest coal-producing country, and coal is the main energy source in our country. With the continuous deepening of coal mining depth, the gas content in coal seams is increasing. Mine gas is not only a kind of green energy, but if it is not effectively controlled, it will cause geological disasters such as coal and gas outbursts and gas explosions. [0003] The mining of extra-thick coal seams will generally result in a large amount of gas gushing out of the working face, and because of the high gas content and pressure of extra-thick coal seams, it is more difficult to effectively control them. At present, the methods of pre-mining coal seam gas control mainly include surface drilling gas drainage, bedding drilling...

AI Technical Summary

Problems solved by technology

[0003] The mining of extra-thick coal seams will generally cause a large amount of gas to flow out of the working face, and because the extra-thick coal seam has a large gas content and high pressure, it is more difficult to effectively control it

At present, the methods of pre-mining coal seam gas control mainly include surface drilling gas drainage, bedding drilling gas drainage, and bed-crossing drilling gas drainage, etc., but these measures are more or less expensive. The hole sealing effect is poor and the gas control area is small. Therefore, a new method is needed to solve the problem

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