Drilling tool assembly used for directional hole-forming underground coal mine and provided with air screw motor and construction method

Abstract

Disclosed is a drilling tool assembly used for directional hole-forming underground a coal mine and provided with an air screw motor and construction method. The drilling tool assembly comprises a directional drill bit, the air screw motor, a lower non-magnetic drill rod, a wireless electromagnetic wave measurement while drilling short section, an upper non-magnetic drill rod, a middle drill rod and a blower which are connected in sequence. The drilling tool assembly can carry out composite drilling and sliding directional drilling for construction: when composite drilling is conducted, the air screw motor drives the directional drill bit to crush rocks in rotatably, meanwhile, the middle drill rod rotates to drive the air screw motor to rotate, boring mud at the bottom of a hole is discharged from the bottom of the hole by compressed air along an annular gap, and the middle drill rod can be used for auxiliary slagging; and when sliding directional drilling is conducted, the middle drill rod does not rotate, the directional drill bit is driven by the air screw motor driven by the compressed air to rotate to crush rocks, and the track of the hole is controlled by changing the elbow orientation of the air screw motor. Thus, according to the drilling tool assembly used for directional hole-forming underground the coal mine and provided with the air screw motor and construction method, the drilling depth of a soft coal seam and the coal seam drilling-encounter rate can be improved greatly, and the drilling gas extraction effect is improved.

Description

technical field [0001] The invention relates to the technical field of underground construction in coal mines, in particular to an air screw motor directional hole-forming drilling tool assembly and a construction method in underground coal mines, which are applied to the long drilling construction of soft coal seams in underground coal mines. Background technique [0002] With the increase of coal mining depth and the expansion of mining scope, it is becoming more and more difficult to control coal seam gas with drilling drainage as the main technical means. Drilling holes for gas drainage in soft and broken coal seams are prone to hole collapse and drill sticking, which makes it difficult to form holes; while rotary drilling is used, it is difficult to control the drilling trajectory, and it is easy to drill to the top (bottom) of the coal seam. Rock, it is impossible to realize long drilling construction along the coal seam, and the gas drainage is not uniform, resulting ...

AI Technical Summary

Problems solved by technology

[0003] At present, the underground directional drilling technology of coal mines uses the hydraulic screw motor as the driving force at the bottom of the hole to drive the drill bit to rotate and break the rock; for soft coal seams, broken, mudstone water-sensitive formations, in order to ensure the stability of the drilling, then Air drilling and auger drilling are mainly used as hole forming methods, and water power cannot be used as flushing medium

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