Pumping screw pump drilling tool system and its construction method for pumping water in underground coal mine boreholes

Abstract

A screw pump drilling tool system for pumping water in underground coal mine boreholes and its construction method. The drilling tool system is composed of active drill pipes, multiple double-wall single-action drill pipes, conversion joints, screw pumps, filter nipples, and drill bits , one end of the active drill rod is connected to one end of multiple double-wall single-acting drill rods, the multiple double-wall single-acting drill rods are connected in sequence, and the other end of the multiple double-wall single-acting drill rods is connected to one end of the conversion joint, The other end of the conversion joint is connected to one end of the screw pump, the other end of the screw pump is connected to one end of the filter sub-joint, and the other end of the filter sub-joint is connected to one end of the drill bit; thus, the present invention can pump It can drain the accumulated water in the directional drilling hole, and can also drain the accumulated water in the conventional downward-sloping drilling hole, with little disturbance to the hole wall, long service life and stable performance of the drilling tool, which can ensure the smooth drainage of the gas in the drilling hole.

Description

technical field [0001] The invention relates to the technical field of drilling tools, in particular to a screw pump drilling tool system and a construction method for pumping water in boreholes underground in coal mines. Background technique [0002] Methane gas is an important hidden danger in the process of coal mining. At present, drilling is generally used for pre-extraction before mining. After reaching the safety standard, the excavation and mining work can be carried out. Due to the trend of the coal seam, some boreholes in the underground coal mine are designed as downward-sloping boreholes or directional boreholes with concave trajectories in some hole sections. Therefore, water accumulation in coal mine boreholes has always been an urgent problem to be solved. [0003] At present, the drainage of downward inclined drilling in coal mines mostly adopts the compressed air drainage technology, which uses the underground compressed air as the power, and the compressed...

AI Technical Summary

Problems solved by technology

This drainage technology requires a long and thin drainage pipe to be lowered into the hole, which is mostly used in conventional downward-sloping drilling. For directional long drilling, it is difficult to lower the drainage pipe to the water accumulation section at the bottom of the hole, and due to the downhole wind pressure and air volume The limitation of deep hole drainage cannot be realized. For soft coal seams, the compressed air row will also cause disturbance to the hole wall, resulting in the collapse of the hole wall and affecting the gas drainage effect.

[0004] Some scholars proposed to adopt the principle of oil well pump, lower the screw pump to the bottom of the hole, and drive the screw pump to pump water through the driving device. However, due to the difference between the gas drainage drilling and the completion of the oil well, the oil well is completed with steel casing, and the screw pump The outer casing is fixed to the inner wall of the steel casing through a special anchoring device, and then the driving device drives the rotor of the screw pump to realize oil pumping. However, the drilling holes for gas drainage are mostly completed with open holes, and the drilling holes are prone to "pregnancy", collapse, and The hole wall of the coal seam is soft, and it is difficult to fix the casing of the screw pump on the hole wall through the anchor device

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