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Patent US4888121A successfully refreshed from Google Patents.
US4888121A
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Compositions and method for controlling precipitation when acidizing sour wells
Assignee: Halliburton Co
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Filing: 1988-04-05
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Granted: 1989-12-19
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Expires: 2008-04-05
Abstract
Abstract A precipitation control additive composition, an acidizing composition for treating a sour well and a method of treating a sour well are provided. An iron sequestering agent, such as aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers, and derivatives thereof and a sulfide modifier, such as aldehyde, acetal, hemiacetal, and many other compounds capable of forming aldehydes in solution are added to a treating solution. The iron sequestering agent cobines with iron present in the solution while the sulfide modifier combines with sulfides present in the solution. By combining with both iron and sulfides present in the solution, the combination of an iron sequestering agent and a sulfide modifier effectively inhibits precipitation of ferric hydroxide, ferrous sulfide and free sulfur from the solution. As a result, formation and other serious damage is prevented.
Inventors
- 👤 Walter R. Dill
- 👤 Michael L. Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:07
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/52; C09K8/528; C09K8/532; Y; Y10; Y10S; Y10S507/00; Y10S507/933; Y10S507/934
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
145 words
An acidizing composition for treating a sour well comprising: a base acid solution having an initial pH below 1.9; an iron sequestering agent to combine with iron present in said solution comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of said acids and ethers present in an amount of from about 0.25 to about 5 percent by weight of said acid solution; and a sulfide modifier to combine with sulfides present in said solution comprising at least one member selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming an aldehyde in solution, present in an amount of from about 1 to about 4 percent by weight of said acid solution, whereby precipitation of ferric hydroxide, ferrous sulfide and elemental sulfur is inhibited as acid spending occurs.
Claim 2
Dependent Claim
145 words
An acidizing composition for treating a sour well comprising: a base acid solution having an initial pH below 1.9; an iron sequestering agent to combine with iron present in said solution comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of said acids and ethers present in an amount of from about 0.25 to about 5 percent by weight of said acid solution; and a sulfide modifier to combine with sulfides present in said solution comprising at least one member selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming an aldehyde in solution, present in an amount of from about 1 to about 4 percent by weight of said acid solution, whereby precipitation of ferric hydroxide, ferrous sulfide and elemental sulfur is inhibited as acid spending occurs.
Claim 3
Dependent Claim
26 words
The acidizing composition of claim 1 wherein said base acid solution comprises hydrochloric acid or admixtures containing hydrochloric acid and any other mineral or organic acids.
Claim 4
Dependent Claim
29 words
The acidizing composition of claim 1, wherein said iron sequestering agent comprises at least one compound selected from the group consisting of nitrilotriacetic acid and salts of said acid.
Claim 5
Dependent Claim
12 words
The acidizing composition of claim 1 wherein said sulfide modifier comprises aldol.
Claim 6
Dependent Claim
22 words
The acidizing composition of claim 1 further comprising a surface active agent for dispersing said sulfide modifier in said base acid solution.
Claim 7
Dependent Claim
145 words
An acidizing composition that becomes contaminated with iron and sulfides when used comprising: an acid solution having an initial pH below about 1.9; an iron sequestering agent comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of said acids and ethers, present in an amount of from about 0.25 to about 5 percent by weight of said acid solution; and a sulfide modifier comprising at least one member selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming an aldehyde in solution, present in an amount of from about 1 to about 4 percent by weight of said acid solution, whereby precipitation of contaminating iron and sulfides solubilized by said acid solution as ferric hydroxide, ferrous sulfide and free sulfur from the acid solution upon spending is inhibited.
Claim 8
Dependent Claim
145 words
An acidizing composition that becomes contaminated with iron and sulfides when used comprising: an acid solution having an initial pH below about 1.9; an iron sequestering agent comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of said acids and ethers, present in an amount of from about 0.25 to about 5 percent by weight of said acid solution; and a sulfide modifier comprising at least one member selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming an aldehyde in solution, present in an amount of from about 1 to about 4 percent by weight of said acid solution, whereby precipitation of contaminating iron and sulfides solubilized by said acid solution as ferric hydroxide, ferrous sulfide and free sulfur from the acid solution upon spending is inhibited.
Claim 9
Dependent Claim
29 words
The composition of claim 6 wherein said acid solution comprises at least one member selected from the group consisting of hydrochloric acid, acetic acid, formic acid and hydrofluoric acid.
Claim 10
Dependent Claim
28 words
The composition of claim 6 wherein said iron sequestering agent comprises at least one compound selected from the group consisting of nitrilotriacetic acid and salts of said acid.
Claim 11
Dependent Claim
13 words
The composition of claim of claim 6 wherein said sulfide modifier comprises aldol.
Claim 12
Dependent Claim
19 words
The composition of claim 6 further comprising a surface active agent for dispersing said sulfide modifier in said solution.
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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) | 1992-12-18 | 1993-06-19 | 1993-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-18 | 1997-06-19 | 1997-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-18 | 2001-06-19 | 2001-12-19 | $7700.00 | Window Closed / Lapsed |