US4137719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for energy extraction from hot dry rock systems
Assignee: Republic Geothermal Inc
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Filing: 1977-03-17
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Granted: 1979-02-06
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Expires: 1997-03-17
Abstract
Abstract In order to prevent scale formation in a hot dry rock geothermal system, a mixture of acetone and water is utilized as the working fluid. Such fluid reduces the amount of scale formation generally associated with such system.
Inventors
- 👤 Robert W. Rex
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:24
CPC Classifications
F; F24; F24T; F24T10/00; F24T10/20; F03; F03G; F03G4/00; F03G4/074; Y; Y02; Y02E; Y02E10/00; Y02E10/10; Y10; Y10S; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
95 words
A method of operating a hot dry rock geothermal system in which a fluid is injected into an injection well, passes through a geothermal reservoir formation and is recovered in a production well and flashed into a vapor, from which energy is extracted, the improvement comprising utilizing as the fluid a mixture of a ketone and water thereby substantially eliminating problems with scale formation in the system when the heated fluid is flashed to steam and also permitting, because of the lower boiling point of the mixture, operating with geothermal formations having lower rock temperatures.
Claim 2
Independent Claim
95 words
A method of operating a hot dry rock geothermal system in which a fluid is injected into an injection well, passes through a geothermal reservoir formation and is recovered in a production well and flashed into a vapor, from which energy is extracted, the improvement comprising utilizing as the fluid a mixture of a ketone and water thereby substantially eliminating problems with scale formation in the system when the heated fluid is flashed to steam and also permitting, because of the lower boiling point of the mixture, operating with geothermal formations having lower rock temperatures.
Claim 3
Dependent Claim
11 words
The method according to claim 1 wherein said ketone is acetone.
Claim 4
Dependent Claim
16 words
The method according to claim 2 wherein said fluid contains 2-99% acetone and the remainder water.
Claim 5
Dependent Claim
14 words
The method according to claim 3 wherein said fluid contains 10 to 30% acetone.
Claim 6
Dependent Claim
19 words
The method according to claim 1 wherein said energy is extracted by using said vapor to drive a turbine.
Claim 7
Dependent Claim
21 words
The method according to claim 5 and further including condensing the exhaust from said turbine and reinjecting it in the well.
Claim 8
Dependent Claim
16 words
The method according to claim 5 wherein said fluid contains 2-99% acetone and the remainder water.
Claim 9
Dependent Claim
11 words
The method according to claim 6 wherein said ketone is acetone.
Claim 10
Dependent Claim
19 words
An improved fluid for use in a hot dry rock geothermal system comprising a mixture of water and acetone.
Claim 11
Dependent Claim
19 words
An improved fluid for use in a hot dry rock geothermal system comprising a mixture of water and acetone.
Claim 12
Dependent Claim
22 words
The fluid of claim 9 wherein said acetone is present in the amount of 2-99% the remainder of the fluid being water.
Claim 13
Dependent Claim
13 words
The fluid of claim 10 wherein said fluid contains 10 to 30% acetone.
References Cited (Backward Citations)
US3437451A
Cited
US3951794A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-05 | 1982-08-07 | 1983-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-05 | 1986-08-07 | 1987-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-05 | 1990-08-07 | 1991-02-06 | $7700.00 | Window Closed / Lapsed |