US3700280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing oil from an oil shale formation containing nahcolite and dawsonite
Assignee: Shell USA Inc
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Filing: 1971-04-28
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Granted: 1972-10-24
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Expires: 1991-04-28
Abstract
Abstract A new and improved method of recovering hydrocarbons and dawsonite decomposition products from a subterranean oil shale formation containing substantial amounts of nahcolite and dawsonite comprising penetrating said formation with at least one well borehole and forming a cavern therein. A hot fluid is circulated in the upper region of the cavern to effect formation of carbon dioxide by decomposition of the nahcolite and dawsonite thereby causing pressure build-up resulting in fracturization and/or rubbling and enlargement of the cavern, thereafter injecting simultaneously or sequentially into the upper region of the cavern a cooling liquid, and into the rubblized zone a kerogen-pyrolyzing fluid to recover hydrocarbons and final by recovering dawsonite decomposition products by suitable means such as solution mining.
Inventors
- 👤 Michael N Papadopoulos
- 👤 Russell C Ueber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:17
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/2405; E21B43/28; E21B43/281
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
111 words
A method of producing hydrocarbons and dawsonite decomposition products from a subterranean oil shale formation containing rich deposits of nahcolite and dawsonite comprising the steps of: a. penetrating at least one well borehole into an underground nahcolite-dawsonite oil shale formation; b. injecting a nahcolite leaching solution to create a cavern; c. circulating a hot fluid along the cavern roof to release carbon dioxide from the nahcolite and dawsonite and thereby increasing the volume of the cavern by effecting rubbling; d. injecting a cool fluid along the enlarged cavern roof while injecting a kerogen-pyrolyzing fluid into the oil shale rubble and recovery hydrocarbons therefore; and e. recovering water insoluble dawsonite decomposition products.
Claim 2
Independent Claim
111 words
A method of producing hydrocarbons and dawsonite decomposition products from a subterranean oil shale formation containing rich deposits of nahcolite and dawsonite comprising the steps of: a. penetrating at least one well borehole into an underground nahcolite-dawsonite oil shale formation; b. injecting a nahcolite leaching solution to create a cavern; c. circulating a hot fluid along the cavern roof to release carbon dioxide from the nahcolite and dawsonite and thereby increasing the volume of the cavern by effecting rubbling; d. injecting a cool fluid along the enlarged cavern roof while injecting a kerogen-pyrolyzing fluid into the oil shale rubble and recovery hydrocarbons therefore; and e. recovering water insoluble dawsonite decomposition products.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the leaching solution in step (b) is hot water and the hot fluid in step (c) is steam.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein the decomposed dawsonite is recovered by solution mining.
Claim 5
Dependent Claim
12 words
The method of claim 3 wherein the decomposed dawsonite is essentially analcite.
Claim 6
Independent Claim
117 words
A method of producing hydrocarbons and analcite from an underground oil shale formation rich in nahcolite and dawsonite comprising the steps of: a. penetrating at least one well borehole into an underground oil shale formation rich in nahcolite and dawsonite; b. leaching a portion of the nahcolitE with hot water to create a cavern; c. circulating steam along the roof of cavern to release carbon dioxide from the nahcolite and dawsonite the latter being converted to analcite to enlarge the cavern vertically and rubble the oil shale; d. injecting a cooling fluid along the roof of the cavern; e. injecting steam into the rubbled oil shale and recovering hydrocarbons therefrom; and f. recovering analcite by solution mining.
Claim 7
Independent Claim
117 words
A method of producing hydrocarbons and analcite from an underground oil shale formation rich in nahcolite and dawsonite comprising the steps of: a. penetrating at least one well borehole into an underground oil shale formation rich in nahcolite and dawsonite; b. leaching a portion of the nahcolitE with hot water to create a cavern; c. circulating steam along the roof of cavern to release carbon dioxide from the nahcolite and dawsonite the latter being converted to analcite to enlarge the cavern vertically and rubble the oil shale; d. injecting a cooling fluid along the roof of the cavern; e. injecting steam into the rubbled oil shale and recovering hydrocarbons therefrom; and f. recovering analcite by solution mining.
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) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |