Patent ID: 9273553
Filing Date: 2016-03-01
CPC Classification: E21B,E21C,E21F

Claim Text:
1. A method of draining fluid from a low permeability, gassy coal seam where a borehole in the coal seam would otherwise collapse, and where the coal seam is adjacent a stronger strata which can sustain the integrity of the borehole, comprising: forming two spaced apart boreholes in the stronger strata adjacent to and generally parallel to the coal seam to be drained of gas, without drilling the borehole into the coal seam, said boreholes defining respective gate road locations, and said gate road locations define a longwall section in the coal seam; fracturing the coal seam at the two spaced apart locations via the boreholes to produce fractures that connect the boreholes to the coal seam and degas the two spaced apart areas in the coal seam to the borehole so that the coal seam can be drained of the gas; said fracturing carried out by using a high pressure fluid injected into the borehole, and fracturing the boreholes multiple times at separate locations over the length of each of the boreholes; forming respective gate roads in the spaced apart and degassed areas of the coal seam; and degassing the longwall section of the coal seam between the gate roads to provide permeability to the longwall section of the coal seam, and mining the longwall section of coal.