US5263539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scale inhibition during oil production
Assignee: Baker Petrolite LLC
•
Filing: 1991-12-05
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Granted: 1993-11-23
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Expires: 2011-12-05
Abstract
Abstract A method and composition are provided for reducing occurrence of scale in a subterranean formation during an enhanced oil recovery process. A treatment composition comprising an amino phosphonic acid and a copolymer of an alkenyl sulfonate and an ethylenically unsaturated comonomer is squeezed into the formation.
Inventors
- 👤 Mohammad H. Salimi
- 👤 Karen C. Petty
- 👤 Claudia L. Emmett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:10
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/52; C09K8/528; Y; Y10; Y10S; Y10S507/00; Y10S507/927
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
63 words
A method for treating a subterranean formation which contains low or neutral pH fluids, comprising: introducing into the subterranean formation through a wellbore a treatment composition comprising an amino phosphonic acid and a copolymer of an alkenyl sulfonic acid compound and an ethylenically unsaturated comonomer, wherein the amount of said treatment composition is effective to inhibit the formation of scale in the formation.
Claim 2
Independent Claim
63 words
A method for treating a subterranean formation which contains low or neutral pH fluids, comprising: introducing into the subterranean formation through a wellbore a treatment composition comprising an amino phosphonic acid and a copolymer of an alkenyl sulfonic acid compound and an ethylenically unsaturated comonomer, wherein the amount of said treatment composition is effective to inhibit the formation of scale in the formation.
Claim 3
Dependent Claim
29 words
A method of claim 1 comprising introducing a sufficient volume of filtered water into the subterranean formation for displacing the treatment composition about 5 ft into the subterranean formation.
Claim 4
Dependent Claim
34 words
A method of claim 1 comprising shutting in the wellbore for a sufficient period of time to allow the treatment composition to adsorb to the subterranean formation rock matrix for maximizing scale inhibiting effectiveness.
Claim 5
Dependent Claim
16 words
A method of claim 3 comprising shutting in the wellbore for about 18 to 24 hours.
Claim 6
Dependent Claim
20 words
A method of claim 1 in which the pH of fluid in the subterranean formation is less than about 4.5.
Claim 7
Dependent Claim
18 words
The method of claim 1, in which the amino phosphonic acid comprises an alkylene polyamine-N substituted-methylene phosphonic acid.
Claim 8
Dependent Claim
18 words
The method of claim 1, in which the amino phosphonic acid comprises a bishexamethylene triamine pentamethylene phosphonic acid.
Claim 9
Dependent Claim
16 words
The method of claim 1, in which the amino phosphonic acid alkenyl sulfonic acid/maleic acid copolymer.
Claim 10
Dependent Claim
16 words
The method of claim 1, in which the copolymer comprises as allyl sulfonic acid/maleic acid copolymer.
Claim 11
Dependent Claim
24 words
The method of claim 1, in which the weight ratio of the amino phosphonic acid to the copolymer is about 8-27 to about 4-15.
Claim 12
Independent Claim
58 words
A method for treating a subterranean formation which contains low pH fluids, comprising: introducing into the subterranean formation a treatment composition comprising an amino phosphonic acid and a copolymer of an alkenyl sulfonic acid compound and an ethylenically unsaturated comonomer, wherein the amount of said treatment composition is effective to inhibit the formation of scale in the formation.
Claim 13
Independent Claim
58 words
A method for treating a subterranean formation which contains low pH fluids, comprising: introducing into the subterranean formation a treatment composition comprising an amino phosphonic acid and a copolymer of an alkenyl sulfonic acid compound and an ethylenically unsaturated comonomer, wherein the amount of said treatment composition is effective to inhibit the formation of scale in the formation.
Claim 14
Dependent Claim
21 words
A method of claim 11 in which the subterranean formation is characterized by the presence of iron ions in the fluids.
Claim 15
Dependent Claim
75 words
An enhanced oil recovery process comprising: introducing into a subterranean formation through an injection wellbore a fluid for displacing oil toward a production wellbore; shutting in the production wellbore; introducing into the subterranean formation through the production wellbore a treatment composition comprising an amino phosphonic acid and a copolymer of an alkenyl sulfonic acid compound and an ethylenically unsaturated comonomer for inhibiting formation of scale in the formation; and producing fluids through the production wellbore.
Claim 16
Dependent Claim
75 words
An enhanced oil recovery process comprising: introducing into a subterranean formation through an injection wellbore a fluid for displacing oil toward a production wellbore; shutting in the production wellbore; introducing into the subterranean formation through the production wellbore a treatment composition comprising an amino phosphonic acid and a copolymer of an alkenyl sulfonic acid compound and an ethylenically unsaturated comonomer for inhibiting formation of scale in the formation; and producing fluids through the production wellbore.
Claim 17
Dependent Claim
18 words
The method of claim 13, in which the amino phosphonic acid comprises an alkylene polyamine-N substituted-methylene phosphonic acid.
Claim 18
Dependent Claim
18 words
The method of claim 13, in which the amino phosphonic acid comprises a bishexamethylene triamine pentamethylene phosphonic acid.
Claim 19
Dependent Claim
16 words
The method of claim 13, in which the copolymer comprises an alkenyl sulfonic acid/maleic acid copolymer.
Claim 20
Dependent Claim
16 words
The method of claim 13 in which the copolymer comprises an allyl sulfonic acid/maleic acid copolymer.
Claim 21
Dependent Claim
24 words
The method of claim 13, in which the weight ratio of the amino phosphonic acid to the copolymer is about 8-27 to about 4-15.
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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) | 1996-11-22 | 1997-05-24 | 1997-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-22 | 2001-05-24 | 2001-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-22 | 2005-05-24 | 2005-11-23 | $7700.00 | Window Closed / Lapsed |