Regional gas underground high-pressure jet hole digging, pressure relief and outburst prevention method

Abstract

The invention discloses a regional gas underground high-pressure jet hole digging, pressure relief and outburst prevention method, which comprises the following steps of: arranging a plurality of drilling fields (3) in a bottom board rock gangway (2) of a coal bed (1), and arranging one or more drilling hole positions; after a drilled hole (4) reaches the design depth of the coal bed (1), withdrawing drilling, and putting a jet device, a filter device and a connected drill rod into the drilled hole (4); starting a high-pressure water pump, rotationally cutting the hole wall of the drilled hole (4) in the coal bed (1) by the jet device, performing radial continuous hole expanding and digging on the drilled hole (4) when the drill rod moves along the axial direction of the drilled hole (4) so as to form a pressure relief space, and collecting coal dust carried out by jet water flow; after the hole is dug to a certain depth, adjusting the position of the jet device by changing the numberof the drill rod to continuously dig the hole; and performing gas drainage on the hole dug coal bed (1) according to a conventional method. The method reduces the gas pressure of the coal bed and effectively reduces the outburst risk of the coal bed.

Description

technical field [0001] The invention relates to a pressure-relieving and outburst-preventing method for digging holes with high-pressure jets in underground gas wells in a region, and is especially suitable for a gas outburst-preventing method for eliminating the risk of coal seam outburst in high-gas and low-permeability regions. Background technique [0002] Coal seams contain a large amount of gas, also known as coalbed methane, which is not only a valuable resource, but also an important part of the coal and gas outburst potential in underground coal mining. More than 95% of the coal mines in my country are mined underground, and a large part of the mines have large mining depths, high gas content, high gas pressure, low coal seam permeability, and large gas emissions during the mining process. With the extension of the coal seam mining to the deep part, the outburst risk of the coal seam in the mine is further enhanced. Some shallow coal seams that are non-outburst grad...

AI Technical Summary

Problems solved by technology

With the extension of coal seam mining to the deep part, the outburst risk of the coal seam in the mine is further enhanced, and some shallow coal seams that are non-outburst gradually turn into outburst coal seams after entering the deep part. Coal and gas outburst power phenomenon, which is likely to cause extraordinarily serious gas accidents

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