Axial convex rib hole-cutting, pressure-relief and internal slag discharging drill rod

Abstract

The invention discloses an axial convex rib hole-cutting, pressure-relief and internal slag discharging drill rod comprises hollow rod bodies, flow injecting pipes coaxially arranged inside the rod bodies and supporting pieces for connecting the rod bodies with the flow injecting pipes. Slag discharging channels are formed between the inner walls of the rod bodies and the outer walls of the flow injecting pipes, and air inlet and water inlet channels are formed inside the flow injecting pipes; and axial convex ribs parallel to the axial direction of the rod bodies are arranged on the externalcylindrical faces of the rod bodies, and a plurality of pressure-relief holes are formed in the sides, along the axial convex ribs, of the external cylindrical faces of the rod bodies. When the interior of a drilled hole collapses, coal slag can enter the slag discharging channels through the pressure-relief holes, and thus acting force of the coal slag to the drill rod is released; and meanwhile,the axial convex ribs has the hole digging capability, so that the coal slag is in a thoroughly loose state to enter the slag discharging channels through the pressure-relief holes till a hole collapse area is unblocked.

Description

Technical field [0001] The invention belongs to the technical field of coal mine gas drainage and drilling, and in particular relates to an axial rib cutting and pressure relief internal slag discharge drill pipe suitable for drilling in high-stress coal seams. Background technique [0002] With the increasing depth of coal mining and the deterioration of coal mining conditions, the problems faced by the mining of high-stress coal seams have received increasing attention. In the process of drilling in high-stress coal seams, the deformation of the borehole is large and the deformation speed is fast, and the phenomenon of stuck and broken drilling is prone to occur, resulting in poor hole forming effect, low drilling efficiency, and shallow drilling depth. [0003] At present, there are two types of drill pipes commonly used in the drilling of high-stress coal seams in China: one is spiral (rib, blade) drill pipe based on the principle of mechanical and wind dual-power slagging; the...

AI Technical Summary

Problems solved by technology

During the drilling process of high-stress coal seams, the deformation of the borehole is large and the deformation speed is fast, and the phenomenon of drill sticking and drill breakage is easy to occur, resulting in poor hole forming effect, low drilling efficiency and shallow drilling depth

[0003] At present, there are two kinds of drill pipes commonly used in domestic high-stress coal seam drilling: one is the helical (rib, blade) drill pipe based on the principle of mechanical and wind dual power slagging; the other is based on eddy current loosening and wind force Due to the small rotation radius of the three-edged drill pipe and the auger drill pipe based on the principle of slag discharge, it cannot effectively cut the shrinking or protruding coal body of the hole wall, and the drilling effect is poor.

The triangular drill pipe uses the principle of eddy current to enhance the slag discharge ability in the case of wind slag discharge, but the slag discharge effect is not ideal when the hydraulic slag discharge method is used

[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. There are too many pressure relief holes, the strength of the drill pipe is low, and the drill is prone to breakage. The setting of the pressure relief hole is unreasonable, and there is a pressure relief blind area when the drill pipe rotates

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