Double-layer internal deslagging and anti-blocking drilling tool for soft and outburst coal seam drilling, and use method of drilling tool

Abstract

The invention discloses a double-layer internal deslagging and anti-blocking drilling tool for soft and outburst coal seam drilling, and a use method of the drilling tool. The drilling tool comprises a rotary sealing water supply device or a rotary sealing air supply device, a double-layer internal deslagging and anti-blocking drilling rod and a central backflow drilling bit, wherein the rotary sealing water supply device or the rotary sealing air supply device is connected with the double-layer internal deslagging and anti-blocking drilling rod on a drilling machine, and the central backflow drilling bit is mounted at the front end of the double-layer internal deslagging and anti-blocking drilling rod. The use method of the drilling tool comprises the steps that a drilling system is started; an air flow or a water flow enters an outer layer channel of the double-layer internal deslagging and anti-blocking drilling rod and reaches the bottom of a drilling hole; the air flow or the water flow reverses out drilling cuttings formed by drilling bit coal breaking along an inner layer channel of the double-layer internal deslagging and anti-blocking drilling rod to enter a slag tapping dust collector connected with the tail part of the drilling rod; and deslagging and dust collection are accomplished. The drilling tool is novel in design; the deslagging is accomplished in a cavity of the drilling rod, so that influences of drilling hole shrinkage and hole wall buckling failure on a drilling hole deslagging space can be avoided effectively; the deslagging is accomplished in the inner layer channel of the drilling rod, so that the dust collection is more effective; and drilling, anti-sloughing and dust collection integrated operation is realized.

Description

technical field [0001] The invention belongs to the technical field of gas drainage drilling construction in outburst coal seams of coal mines, and in particular relates to a slag discharge and anti-blocking drilling tool used for drilling in soft outburst coal seams into double-layer inner layers and a use method thereof. Background technique [0002] Mine gas control relies on gas drainage technology. Due to the influence of coal seam geological conditions, the application of safe and reliable surface well drainage is limited. At present, underground gas drainage is still the main measure for gas drainage, while gas drainage is based on pore-forming technology. For a long time, drilling technology in outburst coal seams has been recognized as a difficult gas control problem at home and abroad. Drilling in outburst coal seams is especially difficult in soft coal seams. Affected by ground stress and gas pressure, soft coal drilling shrinks severely, and local instability and...

AI Technical Summary

Problems solved by technology

Currently commonly used drilling tools, the slagging power is usually fluid slagging and mechanical slagging. Due to the high efficiency of fluid slagging, it is widely used in soft coal seam drilling. Fluid slagging usually enters from the drill pipe cavity. At the bottom of the borehole, the slag discharge space is the annular space between the borehole wall and the drill pipe. Therefore, the deformation and damage of the hole wall have a great influence on the change of the slag discharge space, and the borehole is prone to blockage. The depth of the borehole and the drilling efficiency are greatly affected, which is also the root cause of the difficulty in drilling soft coal

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