US4102397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing an underground coal deposit for in situ production
Assignee: In Situ Technology Inc
•
Filing: 1977-03-07
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Granted: 1978-07-25
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Expires: 1997-03-07
Abstract
Abstract A previously mined underground coal deposit is sealed so that the underground void space can be pressurized for production by in situ techniques. Excavated communication passages are sealed by barricades which are further sealed by applying hydrostatic head pressure. Subsidence cracks are sealed by injection of mud slurry with additional sealing effected by maintaining hydrostatic head pressure with a column of the slurry. In situ production wells are drilled into the coal with hermetic seal accomplished in part by cementing a portion of the liner to the well bore and in part by the hydrostatic head pressure of a mud slurry positioned above the cement seal. Coal is ignited and burn patterns are established to cause reasonably uniform subsidence.
Inventors
- 👤 Ruel C. Terry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:04
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/30; E21B43/305; E21B33/00; E21B33/10; E21B33/13; E21B33/138; E21B43/16; E21B43/24; E21B43/243; E21B43/247
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
214 words
A method of producing an underground coal deposit comprising the steps of: establishing first communication passage between the surface of the earth and an underground coal deposit, setting a liner within the said first communication passage, the lowermost point of said liner being positioned apart from the uppermost portion of the said underground coal deposit, establishing a first hermetic seal between the said liner and the overburden on the periphery of the said first communication passage, the said first hermetic seal being positioned at the lowermost portion of the said liner with the resultant remainder of the annulus between the said liner and the said periphery of the first communication passage being in fluid communication with the earth's atmosphere, establishing a second hermetic seal between the said liner and the atmosphere, the said second hermetic seal being positioned on the uppermost portion of the said liner, establishing a fluid injection means in the uppermost portion of the said liner, establishing fluid withdrawal means in the uppermost portion of the said liner, then establishing a third hermetic seal by injecting a fluid in the annulus between the said liner and periphery of the said first communication passage, the said fluid forming a column of fluid in the said annulus above the said first hermetic seal.
Claim 2
Independent Claim
214 words
A method of producing an underground coal deposit comprising the steps of: establishing first communication passage between the surface of the earth and an underground coal deposit, setting a liner within the said first communication passage, the lowermost point of said liner being positioned apart from the uppermost portion of the said underground coal deposit, establishing a first hermetic seal between the said liner and the overburden on the periphery of the said first communication passage, the said first hermetic seal being positioned at the lowermost portion of the said liner with the resultant remainder of the annulus between the said liner and the said periphery of the first communication passage being in fluid communication with the earth's atmosphere, establishing a second hermetic seal between the said liner and the atmosphere, the said second hermetic seal being positioned on the uppermost portion of the said liner, establishing a fluid injection means in the uppermost portion of the said liner, establishing fluid withdrawal means in the uppermost portion of the said liner, then establishing a third hermetic seal by injecting a fluid in the annulus between the said liner and periphery of the said first communication passage, the said fluid forming a column of fluid in the said annulus above the said first hermetic seal.
Claim 3
Dependent Claim
30 words
The method of claim 1 further including the steps igniting the said underground coal deposit, injecting an oxidizer through the said fluid injection means, and gasifying the said underground coal.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein the said igniting of the said underground coal deposit is attained by dropping hot charcoal briquettes into the said underground coal deposit.
Claim 5
Dependent Claim
19 words
The method of claim 2 further including the steps of terminating the said injecting an oxidizer, then injecting steam.
Claim 6
Dependent Claim
20 words
The method of claim 2 further including the steps of terminating the said injection of an oxidizer, then injecting water.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein the said fluid is a slurry composed of a carrier liquid with suspended solid substances.
Claim 8
Dependent Claim
58 words
The method of claim 1 further including the step of establishing a second communication passage between the surface of the earth and an underground coal deposit, the said second communication passage being spaced apart from the said first communication passage and the said second communication passage being established in the same manner as the said first communication passage.
Claim 9
Dependent Claim
59 words
The method of claim 7 further including the steps of igniting the said underground coal deposit, injecting an oxidizer through the said fluid injection means in the said first communication passage, gasifying the said underground coal, then withdrawing the produced fluids from the said underground coal deposit through the said fluid withdrawal means in the said second communication passage.
Claim 10
Dependent Claim
32 words
The method of claim 8 further including the step of establishing back pressure in the said fluid withdrawal means with the resultant increase in mine pressure in the said underground coal deposit.
Claim 11
Dependent Claim
23 words
The method of claim 1 further including the steps of emplacing explosives within the said underground coal deposit, then detonating the said explosives.
Claim 12
Dependent Claim
37 words
The method of claim 1 further including the steps of installing a slurry injection tubing, the lowermost portion of the said tubing being immersed in the said fluid, then circulating the said fluid within the said annulus.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-24 | 1982-01-23 | 1982-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-24 | 1986-01-23 | 1986-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-24 | 1990-01-23 | 1990-07-25 | $7700.00 | Window Closed / Lapsed |