US4052857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Geothermal energy from salt formations
Assignee: Dow Chemical Co
•
Filing: 1976-10-06
•
Granted: 1977-10-11
•
Expires: 1996-10-06
Abstract
Abstract A method of obtaining geothermal energy from salt formations in which a well is drilled and cased into a suitable salt formation to a depth where the temperature is such that the salt behaves plastically. A weighted, closed end pipe is inserted into the well with its lower, closed end at about the bottom of the salt formation and thereafter an insulated open end pipe is inserted, after the weight has been removed from the closed end pipe, within said closed end pipe, thus forming a double pipe heat exchanger. A heat exchange fluid is circulated, usually in a closed loop, through the double pipe heat exchanger, an energy extracting means, such as, for example, a steam generator or an hydraulic turbine, and back through the heat exchanger.
Inventors
- 👤 Sidney J. Altschuler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:40
CPC Classifications
F; F24; F24T; F24T10/00; F24T10/10; F24T10/13; F24T10/17; F03; F03G; F03G4/00; F03G4/074; Y; Y02; Y02E; Y02E10/00; Y02E10/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
126 words
A method of extracting geothermal energy comprising the steps of: a. drilling and casing a well into a rock salt formation to a depth at which the rock salt behaves plastically; b. inserting a closed end pipe into the well said pipe being filled with removable weighted material; c. sinking the pipe in the plastic salt to a depth at which the calculated energy output is of a selected value; d. inserting an insulated pipe within the sunken closed end pipe, said closed end pipe and said insulated pipe thus forming, in combination, a double pipe heat exchanger; e. circulating a heat exchange fluid through both the double pipe heat exchanger and through an energy extracting means; and f. recovering energy from the heat exchange fluid.
Claim 2
Independent Claim
126 words
A method of extracting geothermal energy comprising the steps of: a. drilling and casing a well into a rock salt formation to a depth at which the rock salt behaves plastically; b. inserting a closed end pipe into the well said pipe being filled with removable weighted material; c. sinking the pipe in the plastic salt to a depth at which the calculated energy output is of a selected value; d. inserting an insulated pipe within the sunken closed end pipe, said closed end pipe and said insulated pipe thus forming, in combination, a double pipe heat exchanger; e. circulating a heat exchange fluid through both the double pipe heat exchanger and through an energy extracting means; and f. recovering energy from the heat exchange fluid.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein, intermediate steps (c) and (d), some of or all of said weighted material is removed from said closed pipe end.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein the weighted material has a density greater than the density of the plastic salt.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein said energy generating means is an electrical energy generator.
Claim 6
Dependent Claim
18 words
The method of claim 4 wherein said generator is powered by heat energy from the heat exchange fluid.
Claim 7
Dependent Claim
18 words
The method of claim 4 wherein said generator is powered by kinetic energy from the heat exchange fluid.
References Cited (Backward Citations)
US3274769A
Cited
US3911683A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |