US4342484A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Well stimulation for solution mining
Assignee: Kennecott Utah Copper LLC
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Filing: 1975-08-14
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Granted: 1982-08-03
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Expires: 1995-08-14
Abstract
Abstract Methods for increasing the permeability of a subterranean igneous rock formation penetrated by at least one well where a hydraulic fluid is injected into the formation at a pressure sufficient to cause diffusion into the natural fractures thereof and thus increase the cross-sectional area thereof, maintaining the pressure and injecting a second fluid which results, by the use thereof, in substantially maintaining the increased cross-sectional area after the pressure is reduced.
Inventors
- 👤 Donald H. Davidson
- 👤 Ray V. Huff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:34
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/28; E21B43/283; C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/80; E21B43/25; E21B43/26; E21B43/267; E21B43/27
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
176 words
A method for increasing the permeability of a metal value containing subterranean igneous rock formation penetrated by at least one well which extends from the surface of the earth into the formation comprising the steps of injecting, at a pressure below the pressure producing new fractures in the formation, a hydraulic fluid through said well into the subterranean igneous rock formation at a pressure sufficient whereby said fluid diffuses into natural fractures in the igneous rock formation surrounding said well and causes said natural fractures in the igneous rock formation surrounding said well to increase in at least the cross-sectional area thereof; and, while maintaining said pressure, injecting as a second fluid a fluid, selected from the group consisting of a propping fluid and a propping fluid in combination with an acidic solution, an alkaline solution, oxidizing agents, and mixtures thereof wherein the injecting is into said natural fractures through said well whereby the use of said second fluid substantially results in maintaining the increased cross-sectional area of said natural fractures after the pressure is reduced.
Claim 2
Independent Claim
176 words
A method for increasing the permeability of a metal value containing subterranean igneous rock formation penetrated by at least one well which extends from the surface of the earth into the formation comprising the steps of injecting, at a pressure below the pressure producing new fractures in the formation, a hydraulic fluid through said well into the subterranean igneous rock formation at a pressure sufficient whereby said fluid diffuses into natural fractures in the igneous rock formation surrounding said well and causes said natural fractures in the igneous rock formation surrounding said well to increase in at least the cross-sectional area thereof; and, while maintaining said pressure, injecting as a second fluid a fluid, selected from the group consisting of a propping fluid and a propping fluid in combination with an acidic solution, an alkaline solution, oxidizing agents, and mixtures thereof wherein the injecting is into said natural fractures through said well whereby the use of said second fluid substantially results in maintaining the increased cross-sectional area of said natural fractures after the pressure is reduced.
Claim 3
Dependent Claim
18 words
The method as set forth in claim 1 wherein the subterranean igneous rock formation contains copper metal values.
Claim 4
Dependent Claim
56 words
The method as set forth in claim 1 wherein the hydraulic fluid is water which is injected into said well of from 1,000 to 10,000 feet deep at a pressure of from about 1,000 psig to about 10,000 psig per foot of well depth, and below the pressure producing new fractures in the igneous rock formation.
Claim 5
Dependent Claim
39 words
The method as set forth in claim 1 wherein said second fluid is an aqueous slurry containing a propping agent selected from the group consisting of sand, walnut shells, glass beads, metal pellets, plastics, ceramic granules and mixtures thereof.
Claim 6
Dependent Claim
17 words
The method as set forth in claim 2 wherein the igneous rock formation contains chalcopyrite and pyrite.
Claim 7
Dependent Claim
42 words
The method as set forth in claim 4 wherein said second fluid further comprises an acidic solution which is capable of reacting with igneous rock in said subterranean igneous rock formation to increase at least the cross-sectional area of said natural fractures.
Claim 8
Dependent Claim
17 words
The method as set forth in claim 4 wherein said second fluid further contains an oxidizing agent.
Claim 9
Dependent Claim
19 words
The method as set forth in claim 6 wherein said acidic solution comprises a mixture of HF and HCl.
Claim 10
Dependent Claim
22 words
The method as set forth in claim 6 wherein said acidic solution comprises a mixture of H 2 SO 4 and HCl.
Claim 11
Dependent Claim
19 words
The method as set forth in claim 7 wherein said oxidizing agent comprises an aqueous solution of ferric sulfate.
Claim 12
Dependent Claim
29 words
The method as set forth in claim 4 wherein said second fluid further comprises a mixture of H 2 SO 4 and Fe 2 (SO 4 ) 3 .
Claim 13
Dependent Claim
15 words
The process for claim 4 wherein the second fluid further contains an oxygenated ammoniacal solution.
References Cited (Backward Citations)
US1806499A
Cited
US2789788A
Cited
US3402966A
Cited
US3642068A
Cited
US3574599A
Cited
US3640579A
Cited
US3822916A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-02 | 1986-02-01 | 1986-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-02 | 1990-02-01 | 1990-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-02 | 1994-02-01 | 1994-08-03 | $7700.00 | Window Closed / Lapsed |