RU94028451A - Method for degassing of guiding beds - Google Patents

Abstract

FIELD: mining of gently sloping coal beds. SUBSTANCE: coal-rock strata containing extracted coal bed and guiding beds core divided into lower and upper stages by holes. Lower stage is formed by the first part of holes which are driven in front of breakage face from additional workings driven towards non-mined coal mass from the working outlying the extractable pillar and distance equalling the pitch of the secondary sagging of roof rocks. Mouths of the first part of holes are located beyond the width of zone of plastic deformations adjacent to supported working. The first part of holes are drilled, cased, cemented and sealed to the boundary of shift of roof rocks with subsequent formation of embryonic slot 39 on contact of guiding bed with roof rocks with the help of slot former made in form of flexible member for formation of the second part of holes of lower stage. Then, the first part of holes of the lower stage are connected to high-pressure pipeline and degassing pipeline for washing and hollow for the second part of holes by means of hydraulic fracture of coal strata in front of breakage face. Upper stage is formed by drilling of additional holes to zone of location of guiding beds, then, casing, cementing and sealing down to the lower boundary of zone of bending of roof rocks, with subsequent connection of them to high-pressure pipeline and degassing pipeline. After repeated hydraulic fracturing of coal strata, when the second part of holes proves to be in the zone of maximum concentration of stresses of the zone of bearing rock pressure stratified fractures are formed which together with hollows of the holes second part, zone fractures formed in zone of caving of worked out source and fractures formed above dome of natural equilibrium adjacent to working outline, form drainage channels in form of gas collectors. Gas collectors ensure captation of methane from coal-rock stratum. EFFECT: prevented formation of layer accumulation of methane in supported working behind the breakage face due to formation of the system of drainage channels in underworked coal-rock strata which ensure methane captation in cases of intensified gas emission from guiding beds. 4 cl, 10 dwg

Claims (1)

The invention can be used in the development of gently sloping coal seams. The objective of the invention is to prevent the formation of layer-by-layer accumulations of methane in a mine supported by a face due to the creation of a drainage channel system in the coal bed undermining to provide methane capture while intensifying gas evolution from satellite formations. For this, the coal-bearing stratum containing the coal seam being developed and the satellite strata are divided into lower and upper tiers using wells. The gas collectors created in this way provide the capture of methane from the carbonaceous stratum, which allows to reduce the increased accumulations of gas in the worked out space, as well as to prevent stratified accumulations of methane over the supported production along its entire length behind the working face.