Coal mine down-hole drilling penetration improvement method based on controllable shock wave technology

Abstract

The invention belongs to the field of energy and coal mine safety, and particularly relates to a coal mine down-hole drilling penetration improvement method based on a controllable shock wave technology. The method aims at solving the problems of high labor intensity and low safety of an existing gas treatment mode. Controllable shock wave generation equipment is pushed to the interior of a drilling hole, and after a hole opening sealing device is installed at a hole opening of the drilling hole, water is injected to the drilling hole; after the drilling hole is fully filled with the water, operation is conducted segment by segment, the middle of each operation segment is used as an operation point of shock waves, and repeated impact is conducted on each operation point multiple times. Under the effect of the injected water in the hole, the shock wave generation equipment does not need to work under the environment with explosive gas, and the shock waves are also efficiently coupled toa coal bed.

Description

Technical field [0001] The invention belongs to the field of energy and coal mine safety, and specifically relates to a method for increasing penetration of coal mine underground drilling based on controllable shock wave technology. Background technique [0002] The geological conditions of the coal seams in my country’s mainland are complex. The main coal fields have undergone multiple phases, multiple directions, and greater strength. The coal seams have been heavily deformed. Most of the coal fields have severely broken coal structures. Coals of Type III and IV account for a heavier proportion. The quality is soft, the firmness coefficient is small, the coal seam permeability is low, and the permeability is generally (0.001-0.1)×10 -3 In the μm range, the gas drainage effect is not good, which makes it difficult to control gas. As the mining activities extend in depth, the occurrence of coal seam gas is characterized by "three highs and one low" (high stress, high gas pressure,...

AI Technical Summary

Problems solved by technology

[0004] Conventional boreholes in coal mines have a hole spacing of 1-2m, a drilling depth of 50-100m, and a pre-pumping time of 15-30 days. The disadvantages are that the amount of drilling is large, the labor intensity of workers is high, the duration of the pre-drainage effect is short, and the effect of coal seam gas drainage is not good;

[0005] Volumetric fracturing technologies such as deep hole pre-splitting blasting or carbon dioxide fracturing can only perform anti-permeability operations on coal seams once in drilling, but not in the entire hole section.

The primary defect is that if the dosage is not well controlled, the borehole will collapse or the borehole will be scrapped; what’s more, the dosage of the powder will be increased due to the pursuit of the effect of pre-splitting the coal seam, which is very likely to cause vicious accidents such as rock burst

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