An axial groove protection hole pressure relief internal slag discharge drill pipe

Abstract

The invention discloses an axial groove hole-protection pressure-relief internal-cinder-discharging drill pipe. The axial groove hole-protection pressure-relief internal-cinder-discharging drill pipecomprises a rod body, a flow injection pipe and a supporting piece, wherein the rod body is hollow, the flow injection pipe and the connecting rod body are arranged in the rod body coaxially, and thesupporting piece is connected with the rod body and the flow injection pipe. A cinder-discharging channel is arranged between the inner wall of the rod body and the outer wall of the flow injection pipe. An air inlet channel and a water inlet channel are arranged inside the flow injection pipe. An axial groove parallel to the axial direction of the rod body is formed in an outer cylindrical surface of the rod body, and a plurality of pressure-relief holes which communicate with the inner cavity of the rod body is formed in the axial groove. When a drill hole collapses, cinders around the drillpipe enter the cinder discharging channel through the pressure-relief holes, the action of the cinders on the drill pipe is released; and at the same time, the axial groove has the ability of drill dredging, so that the surrounding cinders are in a state of loose movement, the cinders through the pressure-relief holes enter the cinder discharging channel, and then a hole collapse area is dredged.

Description

technical field [0001] The invention belongs to the technical field of gas drainage drilling in coal mines, and in particular relates to an axial-groove axial-groove protection hole pressure-relief internal slag discharge drill rod suitable for drilling gas drainage holes in soft coal seams and outburst coal seams. Background technique [0002] Drilling in soft coal seams and outburst coal seams has problems such as difficult slag removal, low drilling efficiency, shallow drilling depth, low hole formation rate, and poor hole formation effect, which directly affect the quality of drilling hole sealing and gas drainage efficiency. [0003] At present, in the drilling of soft and outburst coal seams in China, the commonly used drill pipes are spiral (low spiral) drill pipes and triangular drill pipes. Since the diameter of the helical grooved drill pipe is much smaller than the diameter of the drilled hole, the drill pipe does not have the ability to protect the hole, causing ...

AI Technical Summary

Problems solved by technology

Since the diameter of the helical grooved drill pipe is much smaller than the diameter of the drilled hole, the drill pipe does not have the ability to protect the hole, resulting in instability and deformation of the coal mass on the hole wall or even hole collapse; The rotation diameter of the triangular drill pipe is close to the drilling diameter, but the contact area is small and the hole protection ability is weak. When the triangular drill pipe uses hydraulic slag discharge, the slag discharge effect is not ideal

Moreover, the slag discharge channels of the above two kinds of drill pipes are located between the outer wall of the drill pipe and the hole wall, the shrinkage of the hole diameter or the collapse of the hole has a great influence on the cross section of the slag discharge channel, and the phenomenon of drill sticking is prone to occur during the drilling process

[0004] The published Chinese patent invention "dual-channel porous turbulent flow pressure relief drilling tool for soft coal rock drilling", the patent publication number is: CN203584298U, uses a dual-channel porous turbulent flow pressure relief drill pipe to protect holes and protect slag discharge The channel has a good effect, but the drill pipe does not have the ability to cut the coal protruding from the hole wall, and it is prone to drill sticking and sticking; the number of pressure relief holes is too large, the strength of the drill pipe is low, and the drill pipe is prone to breakage

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