Application of hydraulic fracturing technology in the initial mining and releasing of large-height synthesized mining face in Shangwan Coal Mine
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Abstract
In order to solve the problem of difficult roof collapse during the initial mining period of the working face, based on analyzing the advantages and disadvantages of the existing technology, it is proposed to use the directional long drilling segmental hydraulic fracturing technology to weaken the strength of the roof plate in the initial mining area of the working face and shorten the initial collapse distance, and carry out the engineering application in the working face of 12403 in the Shangwan Coal Mine. The results show that: the theoretical calculation shows that the initial roof fall distance of the working face is 67 m under the untreated condition, and there is a risk of large-area overhanging roof. After the hydraulic fracturing construction, when the working face advances to 15 m, the direct roof begins to fall to fill the mining space, which reduces the release space when the old roof collapses. When advancing to 30 m, the roof of the coal seam starts to collapse in a large area, and the overall pressure of the working face support becomes bigger, and a small amount of flakes are appeared in part of the area. When advancing to 44 m, the old roof is collapsed for the first time, the continuous step of incoming pressure is 9.6 m, which verifies that the application of directional long drilling segmental hydraulic fracturing technology in the initial roof release of the working face is effective.
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