PRELIMINARY DEGASSING OF COAL SERIES AND WORKED-OUT AREA Russian patent published in 2015 - IPC E21F7/00 

FIELD: mining.

SUBSTANCE: invention relates to mining. Claimed process comprises the drilling of wells for perforated casing to fit therein for hydrofracturing to be performed there through. Note here that the coal seam is subjected to overworking/underworking for release and creation the pore-fracture massif of hard and low-permeability rocks. Inclined wells with horizontal ends are drilled in the rock coal seam and, further, into worked-out space to allow drilling gasifying entries to the seam by smaller-diameter bore-holes. Lengthwise fractures are produced via perforated casing in the order following from the face to well mouth and crosswise fractures to release the massif of horizontal tectonic rock pressure component. Fluid with surfactant is forced therein for soil and roof disintegration. Proppant plug is set to prevent a premature methane removal. Thereafter, said plug is washed off. Note here that, first, methane is driven through injection wells to production wells while at cycle termination methane is driven via production wells to injection wells. To acquire the comprehensive data on the massif relieving and on safety, control monitoring measures are taken.

EFFECT: increased face efficiency owing to efficient degassing and unloading of series of worked seams.

3 dwg