US4162707A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating formation to remove ammonium ions
Assignee: Mobil Oil AS
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Filing: 1978-04-20
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Granted: 1979-07-31
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Expires: 1998-04-20
Abstract
Abstract A method of treating a subterranean formation which has undergone an in situ leaching operation which utilzed an ammonium solution as the lixiviant. In such a leach operation, ammonium ions will exchange into the clay in the formation and will present a threat of contamination to any ground waters that may be present in the formation. The present method involves flushing the formation with a halogenated restoration fluid, e.g., chlorinated water having a halogen therein which reacts with ammonia within the formation to decompose the ammonia to nitrogen. The halogenated restoration fluid can be continuously injected or it can be injected as a slug followed by a relatively halogen-free solution to complete the operation. The ammonia concentration of the produced fluids is monitored and when it drops below a desired value, the method is complete.
Inventors
- 👤 Tsoung-Yuan Yan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:07
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; C09K8/74; E; E21; E21B; E21B43/00; E21B43/28; E21B43/34; E21B43/40
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
41 words
A method of treating a subterranean clay-containing formation having ammonium ions absorbed on the clay, the method comprising: flushing said formation with a halogenated restoration fluid having a halogen therein which reacts with ammonia in the formation to decompose said ammonia.
Claim 2
Independent Claim
41 words
A method of treating a subterranean clay-containing formation having ammonium ions absorbed on the clay, the method comprising: flushing said formation with a halogenated restoration fluid having a halogen therein which reacts with ammonia in the formation to decompose said ammonia.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said halogenated restoration fluid comprises: chlorinated water.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein said halogenated restoration fluid comprises: an aqueous solution of a hypochlorite salt.
Claim 5
Dependent Claim
12 words
The method of claim 3 wherein said hypochlorite salt is sodium hypochlorite.
Claim 6
Dependent Claim
27 words
The method of claim 1 including: adjusting the pH of the halogenated restoration fluid to within the range of 7 to 13 by adding an alkaline hydroxide.
Claim 7
Dependent Claim
12 words
The method of claim 5 wherein said alkaline hydroxide is sodium hydroxide.
Claim 8
Independent Claim
93 words
The method of restoring a subterranean clay-containing formation which has been leached with an ammonium solution, said formation having at least one injection well and at least one production well, said method comprising: injecting a halogenated restoration fluid having a halogen therein through said at least one injection well; flowing said halogenated restoration fluid through said formation to react said halogen with ammonia within said formation to decompose said ammonia into nitrogen; producing fluids from said formation through said at least one production well; and monitoring the ammonia concentration in said produced fluids.
Claim 9
Independent Claim
93 words
The method of restoring a subterranean clay-containing formation which has been leached with an ammonium solution, said formation having at least one injection well and at least one production well, said method comprising: injecting a halogenated restoration fluid having a halogen therein through said at least one injection well; flowing said halogenated restoration fluid through said formation to react said halogen with ammonia within said formation to decompose said ammonia into nitrogen; producing fluids from said formation through said at least one production well; and monitoring the ammonia concentration in said produced fluids.
Claim 10
Dependent Claim
27 words
The method of claim 7 including: ceasing the injection of said halogenated restoration fluid when said ammonia concentration in said produced fluids drops below a desired level.
Claim 11
Dependent Claim
27 words
The method of claim 8 wherein the said halogenated restoration fluid is continuously injected until said ammonia concentration in said produced fluids drops below said desired level.
Claim 12
Dependent Claim
37 words
The method of claim 8 wherein said halogenated restoration fluid is injected as a slug followed by the injection of a relatively halogen-free solution until said ammonia concentration in said produced fluids drops below said desired level.
Claim 13
Dependent Claim
18 words
The method of claim 7 wherein said halogenated restoration fluid comprises: an aqueous solution of a hypochlorite salt.
Claim 14
Dependent Claim
12 words
The method of claim 11 wherein said hypochlorite salt is sodium hypochlorite.
Claim 15
Dependent Claim
13 words
The method of claim 7 wherein said halogenated restoration fluid comprises: chlorinated water.
Claim 16
Dependent Claim
17 words
The method of claim 13 wherein said chlorinated water is formed by bubbling chlorine gas through water.
Claim 17
Dependent Claim
28 words
The method of claim 13 wherein said chlorinated water is formed by bubbling chlorine gas through water at a downhole location within said at least one injection well.
Claim 18
Dependent Claim
27 words
The method of claim 7 including: adjusting the pH of said halogenated restoration fluid to within the range of 7 to 13 by adding an alkaline hydroxide.
Claim 19
Dependent Claim
12 words
The method of claim 16 wherein said alkaline hydroxide is sodium hydroxide.
Claim 20
Dependent Claim
27 words
The method of claim 7 including: using at least a portion of the produced fluids to make up said halogenated restoration fluid for recycle in said method.
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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) | 1982-07-30 | 1983-01-29 | 1983-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-30 | 1987-01-29 | 1987-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-30 | 1991-01-29 | 1991-07-31 | $7700.00 | Window Closed / Lapsed |