Patent US4594170A successfully refreshed from Google Patents.
US4594170A
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Method for liquifying chloride-based heavy brine well completion fluids
Assignee: FMC Corp
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Filing: 1984-06-25
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Granted: 1986-06-10
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Expires: 2004-06-25
Abstract
Abstract The invention provides a method to liquify a heavy brine completion fluid containing chlorides. The combination of a persulfate and hydrogen peroxide was found to be more effective than either compound alone, or than a peroxygen plus an activator.
Inventors
- 👤 Richard A. Brown
- 👤 Robert D. Norris
- 👤 Joseph C. Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:37
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/05; Y; Y10; Y10S; Y10S507/00; Y10S507/925
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
77 words
A method to liquify a chloride-based heavy brine completion fluid having a density greater than about 90 kg/m 3 consisting essentially of incorporating into the completion fluid a sufficient amount of hydrogen peroxide and of a persulfate so that the hydrogen peroxide:persulfate mol ratio is between 9:1 and 1:9 and the combined hydrogen peroxide and persulfate content of the completion fluid is at least 1 millimol per liter, thereby liquifying the completion fluid absent added acceleration agents.
Claim 2
Independent Claim
77 words
A method to liquify a chloride-based heavy brine completion fluid having a density greater than about 90 kg/m 3 consisting essentially of incorporating into the completion fluid a sufficient amount of hydrogen peroxide and of a persulfate so that the hydrogen peroxide:persulfate mol ratio is between 9:1 and 1:9 and the combined hydrogen peroxide and persulfate content of the completion fluid is at least 1 millimol per liter, thereby liquifying the completion fluid absent added acceleration agents.
Claim 3
Independent Claim
90 words
A method to liquify a chloride-based heavy brine completion fluid having a density greater than about 90 kg/m 3 consisting essentially of incorporating into the completion fluid a sufficient amount of hydrogen peroxide and of a persulfate selected from the group consisting of ammounium persulfate, potammium persulfate, and sodium persulfate, so that the hydrogen peroxide:persulfate mol ration is between 9:1 and 1:9 and the combined hydrogen peroxide and persulfate content of the completion fluid is at least 1 millimol per liter, thereby liquifying the completion fluid absent added accelerating agents.
Claim 4
Independent Claim
90 words
A method to liquify a chloride-based heavy brine completion fluid having a density greater than about 90 kg/m 3 consisting essentially of incorporating into the completion fluid a sufficient amount of hydrogen peroxide and of a persulfate selected from the group consisting of ammounium persulfate, potammium persulfate, and sodium persulfate, so that the hydrogen peroxide:persulfate mol ration is between 9:1 and 1:9 and the combined hydrogen peroxide and persulfate content of the completion fluid is at least 1 millimol per liter, thereby liquifying the completion fluid absent added accelerating agents.
Claim 5
Dependent Claim
37 words
The method of claim 1 wherein the hydrogen peroxide is generated within the completion fluid from a compound selected from the group consisting of sodium perborate, sodium carbonate peroxide, sodium pyrophosphate peroxide, sodium peroxide, and urea peroxide.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein the persulfate is an alkali metal persulfate or ammonium persulfate.
Claim 7
Dependent Claim
49 words
The method of claim 4 wherein the hydrogen peroxide is generated within the completion fluid by introducing oxygen gas into the completion fluid and passing an electric current between an anode and a cathode immersed in the completion fluid, thereby reducing the oxygen to hydrogen peroxide at the cathode.
Claim 8
Dependent Claim
16 words
The method of claim 2 wherein the hydrogen peroxide:persulfate mol ratio is between 9:1 and 1:1.
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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) | 1989-06-09 | 1989-12-09 | 1990-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-09 | 1993-12-09 | 1994-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-09 | 1997-12-09 | 1998-06-10 | $7700.00 | Window Closed / Lapsed |