Patent US4009957A successfully refreshed from Google Patents.
Patent US3934649A successfully refreshed from Google Patents.
US3934649A
Expired / Lapsed
US
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Method for removal of methane from coalbeds
Assignee: Energy Research and Development Administration ERDA
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Filing: 1974-07-25
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Granted: 1976-01-27
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Expires: 1994-07-25
Abstract
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.
Inventors
- 👤 Joseph Pasini, III
- 👤 William K. Overbey, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:32
CPC Classifications
E; E21; E21F; E21F7/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
88 words
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.
Claim 2
Independent Claim
88 words
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.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein the major natural fracture system of the coal is the face cleats.
Claim 4
Dependent Claim
20 words
A method according to claim 1 wherein the major natural fracture direction of the coal is in the extension joints.
Claim 5
Dependent Claim
17 words
A method according to claim 1 wherein the methane is released by hydraulic fracturing of the coalbed.
Claim 6
Dependent Claim
16 words
A method according to claim 1 wherein a plurality of boreholes are drilled into the coalbed.
Claim 7
Dependent Claim
41 words
A method according to claim 5 wherein the borehole is initiated at an angle of deviation from the vertical and descends as a curved bore of predetermined radius of curvature until it intersects the coalbed in its major natural fracture system.
Claim 8
Dependent Claim
28 words
A method according to claim 6 wherein the angle of deviation from vertical of the borehole increases at a uniform five degrees per 100 feet of drilled hole.
Claim 9
Dependent Claim
27 words
A method according to claim 7 wherein the methane is released from each fracture made in the coalbed and is recovered at the surface of the borehole.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-26 | 1979-07-28 | 1980-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-26 | 1983-07-28 | 1984-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-26 | 1987-07-28 | 1988-01-27 | $7700.00 | Window Closed / Lapsed |