METHOD FOR DEVELOPING A THICK SEAM WITH TOUGH COAL AND DIFFICULT ROOFING ROCKS Russian patent published in 2023 - IPC E21C41/18 E21C37/12 

FIELD: mining.

SUBSTANCE: method for developing a thick seam with strong coal and hard-to-crush roof rocks includes rock pressure control by complete collapse of the roof and preparation of the coal massif of the under-roof stratum for release of the seam by hydraulic fracturing. The same coal wells are used, from each, two or three directed hydraulic fracturing of the roof rocks is first carried out in sequence from the periphery to the layer near the formation soil, the distance between which is taken not less than the maximum size of the outlet window of the powered prop section. Then several interval hydraulic fractures in the coal mass of the under-roofing stratum in the same sequence are done, the number of which is taken depending on the thickness of the under-roofing stratum, and the distance between them on the required size of the pieces of produced coal, but not more than the minimum size of the outlet window. The distance between coal wells is taken equal to the landing step of the hard-to-collapse roof along the extraction column, and to two radii of directional hydraulic fracture propagation across the column. Between the coal-bearing wells, additional formation wells are located, through which interval hydraulic fracturing of the coal massif of the under-roofing stratum is carried out. The distance between additional reservoir wells is assumed to be equal to two radii of fracture propagation of interval hydraulic fracturing.

EFFECT: increased efficiency and safety of development.

1 cl, 2 dwg