Method for removal of methane from coalbeds
AssigneeThe United States of America as represented by the United States Energy Research and Development Administration
InventorsJoseph Pasini, III, William K. Overbey, Jr.
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Abstract
A method for removing methane gas from underground coalbeds prior to mining the coal which comprises drilling at least one borehole from the surface into the coalbed. The borehole is started at a slant rather than directly vertically, and as it descends, a gradual curve is followed until a horizontal position is reached where the desired portion of the coalbed is intersected. Approaching the coalbed in this manner and fracturing the coalbed in the major natural fraction direction cause release of large amounts of the trapped methane gas.
Claims8
A method for removing methane gas from underground coalbeds prior to mining the coal, which comprises determining the orientation of the major natural fracture system of the coalbed and directionally drilling at least one borehole from the earth's surface into the coalbed, said borehole being initiated at a slant and descending at a gradual curve until a horizontal position is reached as the borehole intersects the major natural fracture system of the coal, allowing the methane gas to be released, and recovering the methane gas from the borehole.
Dependencies are inferred from the claim text.