Underground construction method of hydraulic fracturing on high roof of coal seam group

Abstract

The invention discloses a hydraulic fracturing underground construction method for a high-position roof of a coal seam group, which belongs to the field of coal mining; the steps include: confirming the high-position roof of an upper coal seam; calculating the size of the suspended roof of the high-position roof and the bearing area and rupture area of ​​the upper coal pillar; Determine the coordinates of the fracturing point and construct the L-shaped fracturing drilling; complete the hydraulic fracturing construction of the high-level roof; wherein, the drilling construction and hydraulic fracturing parameters vary with changes in mine geological conditions; through the implementation of the present invention, It can reduce the overhang length and broken block degree of the high-level roof, alleviate the strong dynamic load pressure on the working face and reduce the risk of roof cutting and press frame accidents. It is an economical, reasonable, safe and feasible hydraulic fracturing underground construction method.

Description

technical field [0001] The invention relates to the field of coal mining, in particular to an underground construction method of hydraulic fracturing on a high roof of a coal seam group. Background technique [0002] In the mining of coal seam groups, the upper coal seam often leaves residual coal pillars in the protection mining area and roadway, which play the role of transmitting high roof loads, and stress concentration occurs in the floor area. When the lower working face is mined below the coal pillar, it will cause a series of problems: (1) the working face is in the stress-increased area, the support pressure is high, and the support effect is poor; (2) the roof above the residual coal pillar may have secondary fractures, The formed vertical shear force causes roof cutting accidents in the lower working face; (3) The coal pillar is subject to high static load for a long time, and it is prone to large-scale collapse, which leads to the overall structural instability o...

AI Technical Summary

Problems solved by technology

When the lower working face is mined below the coal pillar, it will cause a series of problems: (1) the working face is in the stress-increased area, the support pressure is high, and the support effect is poor; (2) the roof above the residual coal pillar may have secondary fractures, The formed vertical shear force causes roof cutting accidents in the lower working face; (3) The coal pillar is subject to high static load for a long time, and it is prone to large-scale collapse, which leads to the overall structural instability of the interlayer roof of the coal seam group and the strong mining of the lower working face. pressure display

However, the safety of blasting technology is poor and the degree of pollution is high. During the construction process, it may cause impact mine pressure accidents, and even communicate with the gas and flammable gas in the upper mined-out area, causing fire and harmful gas leakage, etc., which limits its application scope.

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