Networked presplitting technology for high-position dirt band layer of extra-thick coal seam based on hydraulic fracturing

Abstract

The invention discloses a networked presplitting technology for a high-position dirt band layer of an extra-thick coal seam based on hydraulic fracturing. The networked presplitting technology comprises the following steps that a top coal structure of a fully mechanized caving face is observed; top coal fracturing parameters of the fully mechanized caving face are determined; fracturing drilling construction and grooving are conducted on top coal of the fully mechanized caving face; the fully mechanized caving face fracturing drill hole is subjected to drill hole sealing; high-pressure hydraulic fracturing is performed on the top coal of the fully mechanized caving face; the hydraulic fracturing effect of the fully mechanized caving face is analyzed; the step of conducting fracturing drilling construction and slotting on the top coal of the fully mechanized caving face comprises the steps that a plurality of fracturing drilling holes perpendicular to the top face of the fully mechanized caving face are formed in the top coal of the fully mechanized caving face; a plurality of fracturing drill holes which deflect towards the working face by an angle are formed in the top face of the rail gate road and the top face of the transportation gate road; and a plurality of transverse cutting grooves are formed in the part, located in the high-position dirt band layer, of the fracturing drill hole. Therefore, the high-position thick and hard dirt band layer in the coal seam can be pre-split and crushed, effective mining of the coal seam above the dirt band layer is achieved, and waste of resources is reduced.

Description

technical field [0001] The invention relates to the technical field of mining and utilization of coal mine resources, in particular to a fully mechanized caving mining method based on the networked pre-cracking technology of hydraulic fracturing in extra-thick coal seam and high-position gangue layer. Background technique [0002] There are a large number of ultra-thick coal seams with shallow burial depth, hard coal, and coal seam thickness of 9-15m in large mining areas such as Shaanxi and Inner Mongolia in western China. The mining height is 8.8m), and layered mining has problems such as complicated process, low efficiency, poor benefit, and difficulty in lower layered mining. This type of coal seam is very suitable for fully mechanized caving mining with large mining height, but with the continuous increase of the thickness of the primary mining of fully mechanized caving mining, the top coal has changed from a single coal body to a composite top coal with multi-layer th...

AI Technical Summary

Problems solved by technology

The high-level thick and hard gangue layer with high strength not only has poor crushing effect and many large pieces, but also affects the crushing and caving of the coal seam above the gangue layer, resulting in poor overall crushing effect of the top coal and low discharge rate.

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