Method and device for conducting hydraulic jet self-propelled drilling to improve gas permeability of coal seam

Abstract

The invention discloses a hydraulic jet self-propelled drilling method and device. The device comprises a water tank, a high-pressure pump, a high-pressure energy storage tank, a high-pressure hose supplying device, a drilling machine, an orientator, a high-pressure hose, a steering gear, a drill rod and a self-propelled drill bit. According to the method, a pilot hole is drilled firstly in a coal seam, the steering gear is installed in the pilot hole, the self-propelled drill bit enters the steering gear along the drill rod and is used for radial drilling along the pilot hole under the guidance of the steering gear, the self-propelled drill bit recedes to the position of the steering gear when radial drilling is conducted to a preset depth, the angle of the steering gear is adjusted by shifting the gear of the orientator so that radial drilling can be conducted in another direction, and a tree-shaped drilling system with the pilot hole as the trunk and radial holes formed in a radiating mode is formed through repeat drilling for gas extraction. The device is simple in structure, convenient to operate, and capable of reducing the number of gas extraction holes remarkably, widening the pressure relieving range of each drill hole, improving the gas permeability of the coal seam effectively, shortening gas extraction time and improving the gas extraction quantity of each hole effectively.

Description

technical field [0001] The invention relates to a coal seam extraction technology, in particular to a drilling device and method for a coal seam extraction hole. Background technique [0002] In recent years, with the continuous increase of the underground development depth of coal mines and the continuous development of coal mine production, the amount of gas in mines has also continued to increase. Coal and gas outbursts have become the most serious disasters in coal mines, and gas pressure is the most serious disaster in coal mines. The main driving force that is prominent with gas, so the effective extraction of gas is of great significance to the control of gas. At present, the coal seams in most coal mines in China are generally soft and low-permeability coal seams. In terms of gas control, methods such as hydraulic fracturing, hydraulic slotting, and intensive drilling of gas drainage holes are mainly used to improve the gas permeability coefficient of coal seams. Ho...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a hydraulic jet self-propelled tree-shaped drilling method and device that can increase the air permeability of coal seams, so as to solve the problems of low gas drainage volume, heavy workload, and low efficiency in low air permeability coal seams.

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