High-pressure water jet punching-drilling-expanding-cutting integrated antireflection device for coal seam, and related method

Abstract

The invention discloses a high-pressure water jet punching-drilling-expanding-cutting integrated antireflection device for coal seam, which comprises a drilling machine, a drilling rod and a drill bit. The drill bit comprises a cylindrical body, wherein the front end of the body extends forward to form a cone-like reaming portion. A reaming cutter is fixed on the conical surface of the reaming cutter. The end face of the small head end of reaming portion extends forward to form a drilling cutter. The rear end of the body is extended backward to form a slitting portion, and the rear end of the slitting portion is fixedly connected with the drilling rod. Pore passages allowing liquid to pass through are provided in the reaming portion, the body and the slitting portion. The rear end of the pore passages is connected with the center hole of drilling rod. The front hole of the pore passages is provided with a punched hole nozzle. A horizontal slit nozzle is provided within the slitting portion, and the pore passages are also provided with a valve core. Therefore, the invention provides a punching-drilling-expanding-cutting integrated antireflection device for the coal seam, and also provides a method for the antireflection of the coal seam by using this punching-drilling-expanding-cutting integrated antireflection device, in order to effectively avoid the borehole deviation, improve the construction environment, reduce water waste and gas waste, and improve work efficiency.

Description

technical field [0001] The invention belongs to the technical field of coal and gas mining, and in particular relates to a coal seam high-pressure water jet punching-drilling-expanding-cutting integrated anti-reflection device and method thereof. Background technique [0002] At present, as one of the clean energy sources with high calorific value, the extraction of coal seam gas has great practical significance. However, in my country, coal seam gas has low gas permeability and gas drainage is difficult. It is often necessary to use artificial strengthening measures to crack the coal body to increase the gas permeability coefficient of the coal seam, thereby increasing the mine gas extraction rate and realizing large-scale drainage and utilization of coal seam gas. The traditional coal seam enhancement methods mainly include hydraulic fracturing and deep hole pre-splitting blasting. However, the hydraulic fractures of hydraulic fracturing generally expand along the directi...

AI Technical Summary

Problems solved by technology

[0005] 1. In the process of drilling hydraulic slot drilling, because the rock formation is a heterogeneous anisotropic material and contains many natural cracks and defects, the drill bit will move along the weak direction ahead during the process of grinding the coal and rock mass. Offset occurs, resulting in a certain offset error between the actual construction drilling position and the design drilling position, which seriously affects the on-site coal seam slotting and gas drainage effect;

[0006] 2. Drilling and reaming and high-pressure hydraulic cutting are two sets of equipment. It is necessary to carry out drilling construction first, and then withdraw the drill pipe to install the hydraulic cutting drill bit for hydraulic cutting. It takes a long time, labor intensity is high, and the efficiency is low.

Moreover, when replacing the drill bit, all the drill pipes must be withdrawn. If the drilling depth is very deep, it will take a longer time. During the process of changing the drill bit, the drill pipe is frequently assembled and disassembled, which will accelerate the wear of the drill pipe and reduce the service life of the drill pipe;

[0007] 3. There is no relevant protection device at the orifice, and during the drilling process of the underground coal seam, because the coal body contains a large amount of high-pressure gas, there is a greater risk of blowout holes, and the drill pipe is likely to be ejected during the drilling construction process. Gas leaks, causing gas to exceed the limit, and even causing casualties;

[0008] 4. There is no waste water circulation recovery system, resulting in a large amount of water in the coal mine working face and poor working conditions on site, which limits the application of this technology on site;

[0009] 5. The drill bit mainly uses rotary grinding to break rocks for drilling, the drill bit is easily damaged, and the economic cost of drilling is large

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