Patent US3779602A successfully refreshed from Google Patents.
US3779602A
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US
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Process for solution mining nahcolite
Assignee: Shell USA Inc
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Filing: 1972-08-07
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Granted: 1973-12-18
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Expires: 1992-08-07
Abstract
Abstract The process of solution mining sodium bicarbonate (e.g., nahcolite) from a subsurface sodium bicarbonate containing, oil shale formation with water is improved by conducting leaching operations at a selected temperature greater than 250*F and adjusting pressure to a particular preferred value for the selected leaching temperature.
Inventors
- 👤 T Beard
- 👤 Meurs P Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:48
CPC Classifications
E; E21; E21B; E21B36/00; E21B43/00; E21B43/28; E21B43/281
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
40 words
The method of claim 1 further comprising producing liquid containing dissolved sodium bicarbonate from a liquid layer adjacent the bottom of the leached zone through a production tubing string using artificial lift means to Lift the liquid to the surface.
Claim 2
Dependent Claim
22 words
The method of claim 2 further comprising withdrawing gas containing CO2 from a gas layer adjacent the top of the leached zone.
Claim 3
Independent Claim
204 words
A method for solution-mining nahcolite from a subsurface oil-shale formation comprising the steps of: traversing a nahcolite-containing zone of the oil-shale formation with a well; extending a production string of tubing into the well to a point adjacent the bottom of the nahcolite-containing zone; extending an injection tubing string into the well to a point adjacent the top of the nahcolite-containing zone; injecting steam into contact with the nahcolite containing zone through the injection tubing at a temperature such that upon contacting the formation at least some of the steam condenses to liquid which liquid flows to the bottom of the nahcolite zone leaching nahcolite therefrom; producing nahcolite-containing aqueous liquid from the nahcolite zone through the production tubing; controlling the rate and temperature of steam injection to maintain a selected temperature of aqueous liquid adjacent the bottom of the nahcolite zone; adjusting the pressure in the aqueous liquid adjacent the bottom of the nahcolite zone to an operating pressure substantially equal to that pressure at which the amount of sodium mineral the aqueous liquid can carry at the selected temperature is a maximum; and maintaining the pressure in the aqueous liquid adjacent the bottom of the nahcolite zone substantially constant at the operating pressure.
Claim 4
Dependent Claim
21 words
The method of claim 4 wherein the operating pressure is a pressure less than that required to hydraulically fracture the formation.
Claim 5
Dependent Claim
28 words
The method of claim 5 wherein the operating pressure is greater than the pressure at which the rate of nahcolite decomposition is a maximum at the selected temperature.
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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |