Top-pressing and bottom-discharging extraction method for crossing hole of steeply inclined coal seam

Abstract

The invention relates to the technical field of gas extraction, and discloses a top-pressing and bottom-discharging extraction method for a crossing hole of a steeply inclined coal seam. The top-pressing and bottom-discharging extraction method for the crossing hole of the steeply inclined coal seam comprises the following steps: step one, site arrangement: a, uniformly arranging a plurality of high-pressure water injection fracturing holes side by side above a mined steeply inclined coal seam roadway to be enhanced in permeability, fixedly communicating a water injection rubber pipe to the inside of each high-pressure water injection fracturing hole, fixedly connecting a plurality of water injection rubber pipes with the same multi-way pipe, fixedly connecting the end, which is away fromthe water injection rubber pipes, of the multi-way pipe with an external fracturing pump, and arranging a high-pressure water injection valve on the pipe wall of the multi-way pipe. By the top-pressing and bottom-discharging extraction method for the crossing hole of the steeply inclined coal seam, upper fracturing permeability enhancement and lower pressure relief drainage can be realized, and rapid drainage work is facilitated.

Description

technical field [0001] The invention relates to the technical field of gas drainage, in particular to a gas drainage method for drilling holes through a steeply inclined coal seam through upward pressure and downward discharge. Background technique [0002] Most mining areas in my country have entered into deep mining, where the in-situ stress of deep coal seams increases, the air permeability of coal seams is lower, and it is more difficult to extract gas. Downhole hydraulic fracturing technology has the advantages of large fracturing range, large pressure relief range, and obvious anti-permeability effect, and has become an effective technical approach for deep low-permeable coal seams to increase permeability and regional pressure relief. [0003] The current downhole hydraulic fracturing technology is arranged in the way of directional hole fracturing. In the process of drainage, it is only necessary to drain the water through the extraction hole. This method is only sui...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the deficiencies of the prior art, the present invention provides a drainage method for steeply inclined coal seam piercing drilling, which has the advantages of being able to realize fracturing and permeability enhancement at the upper part, pressure relief and drainage at the lower part, and facilitate rapid drainage work, etc. It solves that if the high-pressure water in the coal seam cannot be discharged in time, it will not only lead to a large amount of water flow in the subsequent horizontal mining process, which will affect the mining efficiency, but also increase the gas pressure in the coal seam, which will easily cause gas outburst The danger, the safety is low, and it is not convenient for the mining and use of coal seams.

Images