Method for extracting high-pressure hydraulic cave-manufacturing gas from rock roadway crossing hole

Abstract

The invention discloses a method for extracting high-pressure hydraulic cave-manufacturing gas from a rock roadway crossing hole and belongs to the field of a soft high outburst seam gas extracting method. The method is characterized in that upward or downward large-diameter crossing holes are constructed into the coal seam roof or the coal seam floor by drilling and stamping integration equipment in the rock roadway of the soft high outburst seam; the cave is manufactured hydraulically by combining hydraulic fracturing with hydraulic jetting punching; a great cave is established in the coal seam and a fracture expansion region is formed around the cave, so that the coal ground stress is reduced, the bare area of the coal seam is increased, and the permeability of the coal seam, the gas extracting efficiency and the gas extracting quantity are improved. The method has the advantages that the large cave is established in the soft high outburst seam and a huge fracture expansion mesh is formed around the cave, so that the coal ground stress is reduced, the bare area of the coal seam is increased, and the permeability of the coal seam is improved; besides wide space is provided to convey and extract the gas, the gas extracting efficiency and gas extracting quality in the soft high outburst seam can be effectively improved, and a new way to treat the gas in the soft high outburst seam is provided.

Description

technical field [0001] The invention relates to a method for gas extraction in soft and high outburst coal seams, in particular to a method for gas extraction in rock roadway through layer drilling and high-pressure hydraulic cave formation. Background technique [0002] my country's coal-bearing strata are mostly Jurassic and Carboniferous Permian. Most coal seams are low-permeability soft coal seams. Many mining areas have experienced multi-stage uplifts, depressions, folds, and faults. Under stress, the geological conditions are extremely complex, and in some hard coal mining areas, there are also local structural failures, resulting in the development of structural coal, which is characterized by soft coal quality, poor coal seam permeability, and difficulty in gas drainage from the original coal body. my country's coal-bearing strata mostly exist under the conditions of coal seam groups, which extend to the deep year by year with the increase of mining intensity. After e...

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Problems solved by technology

[0004] The object of the present invention is to provide a high-pressure hydraulic hydraulic system for drilling through layers of rock roadway to solve the problems of soft and high-outburst coal seam coal body structure, poor air permeability, high gas content and high pressure, difficulty in gas extraction and high risk of high gas disasters. Cave gas extraction method

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