US4276185A
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US
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Methods and compositions for removing deposits containing iron sulfide from surfaces comprising basic aqueous solutions of particular chelating agents
Assignee: Halliburton Co
•
Filing: 1980-02-04
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Granted: 1981-06-30
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Expires: 2000-02-04
Abstract
Abstract Methods and compositions for removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution. A composition comprised of a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, alkylene polyamine polyacetic acids and mixtures of such chelating agents having a pH in the range of from about 8 to about 10 is brought into contact with the deposits for a period of time sufficient for the deposits to be dissolved therein.
Inventors
- 👤 Larry D. Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:02
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/14; C23G1/19; Y; Y10; Y10S; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
62 words
A method for dissolving iron sulfide deposits with minimal hydrogen sulfide evolution comprising contacting said iron sulfide with a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10.
Claim 2
Independent Claim
62 words
A method for dissolving iron sulfide deposits with minimal hydrogen sulfide evolution comprising contacting said iron sulfide with a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein said chelating agent is present in said solution in an amount in the range of from about 2% to about 10% by weight of said solution.
Claim 4
Dependent Claim
34 words
The method of claim 1 wherein said chelating agent is nitrilotriacetic acid present in said solution in an amount in the range of from about 4% to about 8% by weight of said solution.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein said solution contains ammonia in an amount such that said solution has a pH of about 9.
Claim 6
Dependent Claim
34 words
The method of claim 1 wherein said chelating agent is ethylenediaminetetraacetic acid present in said solution in an amount in the range of from about 4% to about 8% by weight of said solution.
Claim 7
Dependent Claim
47 words
The method of claim 1 wherein said solution is further characterized to include a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said solution in an amount in the range of from about 0.05% to about 0.6% by volume of said solution.
Claim 8
Independent Claim
44 words
A method for dissolving iron sulfide deposits with minimal hydrogen sulfide evolution comprising contacting said iron sulfide with a basic aqueous solution of an alkylenepolyamine polyacetic acid chelating agent, said solution having a pH in the range of from about 8 to about 10.
Claim 9
Independent Claim
44 words
A method for dissolving iron sulfide deposits with minimal hydrogen sulfide evolution comprising contacting said iron sulfide with a basic aqueous solution of an alkylenepolyamine polyacetic acid chelating agent, said solution having a pH in the range of from about 8 to about 10.
Claim 10
Dependent Claim
30 words
The method of claim 7 wherein said chelating agent is ethylenediaminetetraacetic acid and said solution contains ammonia in an amount such that said solution has a pH of about 9.
Claim 11
Dependent Claim
32 words
The method of claim 8 wherein said ethylenediaminetetraacetic acid is present in said solution in an amount in the range of from about 4% to about 8% by weight of said solution.
Claim 12
Dependent Claim
47 words
The method of claim 9 wherein said solution is further characterized to include a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said solution in an amount in the range of from about 0.1% to about 0.3% by volume of said solution.
Claim 13
Independent Claim
91 words
A method for removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution comprising contacting said deposits with a composition consisting essentially of: water; a chelating acid selected from the group consisting of nitrioltriacetic acid and an alkylenepolyamine polyacetic acid present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition; and ammonia present in said composition in an amount such that the pH of said composition is in the range of from about 8 to about 10.
Claim 14
Independent Claim
91 words
A method for removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution comprising contacting said deposits with a composition consisting essentially of: water; a chelating acid selected from the group consisting of nitrioltriacetic acid and an alkylenepolyamine polyacetic acid present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition; and ammonia present in said composition in an amount such that the pH of said composition is in the range of from about 8 to about 10.
Claim 15
Dependent Claim
28 words
The method of claim 11 wherein said alkylenepolyamine polyacetic acid is ethylenediaminetetraacetic acid present in said composition in an amount of about 4% by weight of said composition.
Claim 16
Dependent Claim
26 words
The method of claim 12 wherein said ammonia is present in said composition in an amount such that the pH of said composition is about 9.
Claim 17
Dependent Claim
47 words
The method of claim 13 wherein said composition is further characterized to include a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said composition in an amount in the range of from about 0.1% to about 0.3% by volume of said composition.
Claim 18
Dependent Claim
96 words
An emulsified composition for dissolving deposits containing organic materials and iron sulfide with minimal hydrogen sulfide evolution comprising: a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10; a liquid hydrocarbon solvent for said organic materials; and an emulsifier selected from the group consisting of oxyalkylated phenols and the carboxylate salts thereof, and castor oil ethoxylated with forty moles of ethylene oxide.
Claim 19
Dependent Claim
96 words
An emulsified composition for dissolving deposits containing organic materials and iron sulfide with minimal hydrogen sulfide evolution comprising: a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10; a liquid hydrocarbon solvent for said organic materials; and an emulsifier selected from the group consisting of oxyalkylated phenols and the carboxylate salts thereof, and castor oil ethoxylated with forty moles of ethylene oxide.
Claim 20
Dependent Claim
32 words
The composition of claim 15 wherein said chelating agent is present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition.
Claim 21
Dependent Claim
33 words
The composition of claim 16 wherein said liquid hydrocarbon solvent is present in said composition in an amount in the range of from about 10% to about 50% by volume of said composition.
Claim 22
Dependent Claim
39 words
The composition of claim 17 wherein said emulsifier is castor oil ethoxylated with forty moles of ethylene oxide and is present in said composition in an amount of from about 0.1% to about 1% by volume of said composition.
Claim 23
Dependent Claim
42 words
The composition of claim 15 wherein said chelating agent is nitrilotriacetic acid present in said composition in an amount of about 4% by weight, and said composition contains ammonia in an amount such that said composition has a pH of about 9.
Claim 24
Dependent Claim
18 words
The composition of claim 19 wherein said liquid hydrocarbon solvent for said organic materials is heavy aromatic naphtha.
Claim 25
Dependent Claim
26 words
The composition of claim 20 wherein said heavy aromatic naphtha is present in said composition in an amount of about 30% by volume of said composition.
Claim 26
Dependent Claim
33 words
The composition of claim 21 wherein said emulsifier is castor oil ethoxylated with forty moles of ethylene oxide present in said composition in an amount of about 0.5% by volume of said composition.
Claim 27
Dependent Claim
42 words
The composition of claim 15 wherein said chelating agent is ethylenediaminetetraacetic acid present in said composition in an amount of about 4% by weight, and said composition contains ammonia in an amount such that said composition has a pH of about 9.
Claim 28
Dependent Claim
18 words
The composition of claim 23 wherein said liquid hydrocarbon solvent for said organic materials is heavy aromatic naphtha.
Claim 29
Dependent Claim
26 words
The composition of claim 24 wherein said heavy aromatic naphtha is present in said composition in an amount of about 30% by volume of said composition.
Claim 30
Dependent Claim
33 words
The composition of claim 25 wherein said emulsifier is castor oil ethoxylated with forty moles of ethylene oxide present in said composition in an amount of about 0.5% by volume of said composition.
Claim 31
Dependent Claim
45 words
The composition of claim 26 which is further characterized to include a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said composition in an amount in the range of from about 0.1% to about 0.2% by volume of said composition.
Claim 32
Dependent Claim
36 words
The composition of claim 27 which is further characterized to include benzotriazole coupling agent present in said composition in an amount in the range of from about 0.1% to about 1% by weight of said composition.
Claim 33
Independent Claim
78 words
A method of removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution comprising contacting said deposits for a period of time sufficient to dissolve said deposits with a composition comprised of a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10.
Claim 34
Independent Claim
78 words
A method of removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution comprising contacting said deposits for a period of time sufficient to dissolve said deposits with a composition comprised of a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10.
Claim 35
Dependent Claim
52 words
The method of claim 29 wherein said chelating agent is nitrilotriacetic acid present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition, and said composition contains ammonia in an amount such that said composition has a pH of about 9.
Claim 36
Dependent Claim
52 words
The method of claim 29 wherein said chelating agent is ethylenediaminetetraacetic acid present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition, and said composition contains ammonia in an amount such that the pH of said composition is about 9.
Claim 37
Dependent Claim
47 words
The method of claim 29 wherein said composition is further characterized to include a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said composition in an amount in the range of from about 0.05% to about 0.6% by volume of said composition.
Claim 38
Independent Claim
100 words
A method of removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution comprising circulating a composition at a temperature in the range of from about 200° F. to about 300° F. over said surfaces containing said deposits for a period of time sufficient to dissolve said deposits in said composition, said composition comprising a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10.
Claim 39
Independent Claim
100 words
A method of removing deposits containing iron sulfide from surfaces with minimal hydrogen sulfide evolution comprising circulating a composition at a temperature in the range of from about 200° F. to about 300° F. over said surfaces containing said deposits for a period of time sufficient to dissolve said deposits in said composition, said composition comprising a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10.
Claim 40
Dependent Claim
52 words
The method of claim 33 wherein said chelating agent is nitrilotriacetic acid present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition and said composition contains ammonia in an amount such that said solution has a pH of about 9.
Claim 41
Dependent Claim
52 words
The method of claim 33 wherein said chelating agent is ethylenediaminetetraacetic acid present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition and said composition contains ammonia in an amount such that the pH of said composition is about 9.
Claim 42
Dependent Claim
47 words
The method of claim 33 wherein said composition is further characterized to include a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said composition in an amount in the range of from about 0.05% to about 0.6% by volume of said composition.
Claim 43
Independent Claim
114 words
A method of removing deposits containing organic materials and iron sulfide with minimal hydrogen sulfide evolution comprising contacting said deposits for a period of time sufficient to dissolve said deposits with an emulsified composition comprised of: a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10; a liquid hydrocarbon solvent for said organic materials; and an emulsifier selected from the group consisting of oxyalkylated phenols and the carboxylate salts thereof, and castor oil ethoxylated with forty moles of ethylene oxide.
Claim 44
Independent Claim
114 words
A method of removing deposits containing organic materials and iron sulfide with minimal hydrogen sulfide evolution comprising contacting said deposits for a period of time sufficient to dissolve said deposits with an emulsified composition comprised of: a basic aqueous solution of a chelating agent selected from the group consisting of citric acid, oxalic acid, nitrilotriacetic acid, alkylenepolyamine polyacetic acids and mixtures of said chelating agents, said solution having a pH in the range of from about 8 to about 10; a liquid hydrocarbon solvent for said organic materials; and an emulsifier selected from the group consisting of oxyalkylated phenols and the carboxylate salts thereof, and castor oil ethoxylated with forty moles of ethylene oxide.
Claim 45
Dependent Claim
52 words
The method of claim 37 wherein said chelating agent is nitrilotriacetic acid present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition, and said composition contains ammonia in an amount such that the pH of said composition is about 9.
Claim 46
Dependent Claim
52 words
The method of claim 37 wherein said chelating agent is ethylenediaminetetraacetic acid present in said composition in an amount in the range of from about 4% to about 8% by weight of said composition, and said composition contains ammonia in an amount such that the pH of said composition is about 9.
Claim 47
Dependent Claim
23 words
The method of claim 37 wherein said liquid hydrocarbon solvent is selected from the group consisting of ortho-dichlorobenzene, xylene and heavy aromatic naphtha.
Claim 48
Dependent Claim
36 words
The method of claim 40 wherein said liquid hydrocarbon solvent is heavy aromatic naphtha present in said composition in an amount in the range of from about 10% to about 50% by volume of said composition.
Claim 49
Dependent Claim
40 words
The method of claim 37 wherein said emulsifier is castor oil ethoxylated with forty moles of ethylene oxide present in said composition in an amount in the range of from about 0.1% to about 1% by volume of said composition.
Claim 50
Dependent Claim
47 words
The method of claim 37 wherein said composition is further characterized to include a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said composition in an amount in the range of from about 0.05% to about 0.6% by volume of said composition.
Claim 51
Dependent Claim
38 words
The method of claim 37 wherein said composition is further characterized to include benzotriazole coupling agent present in said composition in an amount in the range of from about 0.1% to about 1.0% by weight of said composition.
Claim 52
Dependent Claim
72 words
The method of claim 37 wherein said chelating agent is ethylenediaminetetraacetic acid present in said composition in an amount of about 4% by weight of said composition, said liquid hydrocarbon solvent is heavy aromatic naphtha present in said composition in an amount of about 30% by volume and said emulsifier is castor oil ethoxylated with forty moles of ethylene oxide present in said composition in an amount of about 0.5% by volume.
Claim 53
Dependent Claim
53 words
The method of claim 45 wherein said composition is further characterized to include a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said composition in an amount of about 0.1% by volume and benzotriazole coupling agent present in said composition in an amount of about 0.3% by weight.
Claim 54
Independent Claim
196 words
A method of removing deposits containing organic materials and iron sulfide from surfaces with minimal hydrogen sulfide evolution comprising: circulating an emulsified composition over said surfaces containing said deposits, said composition being comprised of a basic aqueous solution of ethylenediaminetetraacetic acid chelating agent present in said composition in an amount of about 4% by weight of said composition, heavy aromatic naphtha present in said composition in an amount of about 30% by volume of said composition, castor oil ethoxylated with forty moles of ethylene oxide emulsifier present in said composition in an amount of about 0.5% by volume of said composition, a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said composition in an amount of about 0.1% by volume of said composition and benzotriazole coupling agent present in said composition in an amount of about 0.3% by weight of said composition; heating said composition to a temperature in the range of from about 200° F. to about 300° F. while said composition is circulating over said surfaces; and withdrawing said composition from said surfaces after said composition has circulated thereover for a period of time sufficient to dissolve said deposits.
Claim 55
Independent Claim
196 words
A method of removing deposits containing organic materials and iron sulfide from surfaces with minimal hydrogen sulfide evolution comprising: circulating an emulsified composition over said surfaces containing said deposits, said composition being comprised of a basic aqueous solution of ethylenediaminetetraacetic acid chelating agent present in said composition in an amount of about 4% by weight of said composition, heavy aromatic naphtha present in said composition in an amount of about 30% by volume of said composition, castor oil ethoxylated with forty moles of ethylene oxide emulsifier present in said composition in an amount of about 0.5% by volume of said composition, a corrosion inhibitor comprised of a mixture of an alkylpyridine and dibutylthiourea present in said composition in an amount of about 0.1% by volume of said composition and benzotriazole coupling agent present in said composition in an amount of about 0.3% by weight of said composition; heating said composition to a temperature in the range of from about 200° F. to about 300° F. while said composition is circulating over said surfaces; and withdrawing said composition from said surfaces after said composition has circulated thereover for a period of time sufficient to dissolve said deposits.
References Cited (Backward Citations)
US2403153A
Cited
US2472400A
Cited
US3033214A
Cited
US3066097A
Cited
US3308065A
Cited
US3353995A
Cited
US3794523A
Cited
US4025359A
Cited
US4011097A
Cited
US4032360A
Cited
US4108681A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1984-06-29 | 1984-12-29 | 1985-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-29 | 1988-12-29 | 1989-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-29 | 1992-12-29 | 1993-06-30 | $7700.00 | Window Closed / Lapsed |