Bedding hydraulic punching method

Abstract

The invention discloses a bedding hydraulic punching method. On one side of a pre-mined coal wall, a variable-diameter drill is used to drill holes along the bedding to a deep layer to produce an external small borehole with a thickness of h1 and a diameter of d1 and a thickness of h2. An internal large borehole with a diameter of d2, where d1<d2; after exiting the reducing drill, insert a water injection pipe deep into the borehole, seal the hole and fill it with high-pressure water. The invention solves the problem that gas outburst accidents are easy to occur in bedding mining, and it is difficult to adopt bedding coal mining. The coal wall with a thickness of h1 is formed by using the variable diameter drill as a protective wall, which can prevent the coal seam inside the coal wall from being damaged Prominent accidents occur due to unbalanced forces to protect the safety of workers. It can also increase the water pressure strength, increase the internal pressure of the coal seam, have sufficient cracks, and achieve the permeability enhancement of replacement. Compared with the piercing hydraulic punching method, the present invention has the advantages of simple method, high efficiency, small workload and low cost.

Description

technical field [0001] The invention relates to the technical field of coal mining, in particular to a safe operation method for coal seam layer-by-bed hydraulic punching and wall breaking. Background technique [0002] The underground coal seam is in a long-term high pressure state, and the gas is sealed and compressed in different areas of the coal seam to form a stable structure. However, during the mining process, because the new mining area destroys the balance of the coal seam, the sealed gas will be released suddenly, causing outburst accidents. At present, in the process of coal seam mining, it is usually necessary to drill holes in the coal seam, and use hydraulic fracturing to increase permeability. Downhole fracturing significantly increases the air permeability of the coal seam. The purpose of hydraulic fracturing is to form micro-cracks and through-cracks in the coal body, so that coalbed methane can be quickly migrated out, and provide conditions for the next ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that gas outburst accidents have always been prone to occur in bedding mining, so it is basically afraid to adopt bedding coal mining. It provides a method of hydraulic punching through bedding, which can be suitable for all coal seam structures and is applicable Strong performance, reduce the difficulty of mining, improve the efficiency of hydraulic punching