Pressure-variable dredging method for high-level drilling gas channel

Abstract

The invention relates to the technical field of mine gas extraction and mining, in particular to a pressure-variable dredging method for a high-level drilling gas channel. The pressure-variable dredging method comprises the following steps that a, high-level drilling is conducted on a coal mining working face, drilling construction is conducted on from an air return roadway of the working face tothe coal seam roof, a plurality of drilling fields are designed, and a single set of drilling fields contains ten drilling holes; b, drainage drilling hole valves at the drilling fields are closed fordrainage intermittently for 10 min; c, the drilling holes being closed at the first time are opened, the drilling holes which are not closed are closed, the duration time is from the initial period when the interior of a drainage piping has the clear gravel falling sound to the moment that the sound gradually stops; and d, the step b and c are repeated for 2-3 times. The pressure-variable dredging method increases the overall gas drainage amount of the gas drainage drilling fields and truly embodies the significance of drainage for stope working face gas control, and operation is simple; andthe used labor is less, the consumed time is short, and work can be finished within 30min, and the labor intensity is low.

Description

technical field [0001] The invention relates to the technical field of mine gas drainage, in particular to a method for dredging a high-level borehole gas channel with variable pressure. Background technique [0002] In coal mining, gas disasters have always been one of the main disasters that threaten the safety of coal mine production. Although there have been many technical methods for gas control at home and abroad, limited by geographical and production environment conditions, the overall promotion is not widespread. However, gas drainage technology is still considered to be one of the most effective ways to prevent gas disasters. [0003] Generally, the gas gushing out of the coal mining face mainly comes from the goaf of the overlying stratum. Reduce the high-concentration gas in the overlying layer from gushing to the working face during the mining process. However, the gas extracted will inevitably carry a small amount of fine particles such as rock powder and coa...

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Problems solved by technology

[0004] In order to solve the problem that the particulate matter inside the borehole moves with the negative pressure of the pumping to block the gas flow channel and cause the gas in the upper corner of the overburden gas to drain down the working face, the gas rises, and provides a method for dredging the gas channel in a high-level borehole with variable pressure

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