Abstract: An improved method for the in situ recovery of methane from a plurality of coal seams beneath the earth's surface. At least one borehole is driven from the surface into a selected coal seam wherein a plurality of cavities are formed. The coal walls intermediate said cavities and the strata overlying said cavities are caused to collapse suddenly thereby forming fissure systems into the coal bearing rock strata from which methane is released. The methane is withdrawn via the fissure systems, cavities and the borehole. The cavities may be formed by chemical, physical or mechanical recovery of the coal.

Abstract: For the purpose of in-situ recovery of coal a borehole is driven from the surface in the plane of the coal over at least a large part of its travel, as far as conditions permit. At or near its end this borehole is widened over such a length and to such a width as corresponds with at least twice the deviation to be expected in the horizontal projection of a second borehole which is driven so far as to connect the widened section described above. The widened section is preferably made with the aid of mechanical means.After the boreholes have been linked, the coal is recovered by gasification, dissolution or extraction, whether or not under supercritical conditions and whether or not with attendant chemical/physical disintegration. The method according to the invention is particularly suited for use in the `in-line` gasification technique.