US4495996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for scale removal and scale inhibition in a well penetrating a subterranean formation
Assignee: Atlantic Richfield Co
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Filing: 1983-12-01
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Granted: 1985-01-29
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Expires: 2003-12-01
Abstract
Abstract A method for removing scale and inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from the formation, the method comprising; (a) injecting an aqueous solution of EDTA into the well in an amount and for a time effective to remove scale from the well; and, (b) injecting a scale inhibitor through the well and into the subterranean formation surrounding the well.
Inventors
- 👤 Kevin O. Meyers
- 👤 Harry L. Skillman, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:58
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/52; C09K8/528; Y; Y10; Y10S; Y10S166/00; Y10S166/902; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
95 words
A method for removing scale and inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from said formation, said method comprising; (a) injecting an aqueous solution of a mineral acid into said well in an amount and for a a time effective to remove scale from said well; (b) injecting an aqueous solution of EDTA into said well in an amount and for a time effective to remove scale from said well; and, (c) injecting a scale inhibitor through said well into said formation about said well.
Claim 2
Independent Claim
95 words
A method for removing scale and inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from said formation, said method comprising; (a) injecting an aqueous solution of a mineral acid into said well in an amount and for a a time effective to remove scale from said well; (b) injecting an aqueous solution of EDTA into said well in an amount and for a time effective to remove scale from said well; and, (c) injecting a scale inhibitor through said well into said formation about said well.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein said scale comprises calcium carbonate.
Claim 4
Dependent Claim
14 words
The method of claim 2 wherein said scale inhibitor comprises a phosphonic acid derivative.
Claim 5
Dependent Claim
13 words
The method of claim 2 wherein said scale inhibitor comprises a phosphate ester.
Claim 6
Dependent Claim
11 words
The method of claim 2 wherein said scale inhibitor comprises polyacrylamides.
Claim 7
Dependent Claim
30 words
The method of claim 2 wherein said injection of said aqueous solution of EDTA is controlled to contact the well casing perforations and portions of said formation near said well.
References Cited (Backward Citations)
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US3529666A
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Cited
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US4213866A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-29 | 1988-07-30 | 1989-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-29 | 1992-07-30 | 1993-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-29 | 1996-07-30 | 1997-01-29 | $7700.00 | Window Closed / Lapsed |