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US4741400A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for scale inhibition in a well penetrating a subterranean formation

Assignee: Atlantic Richfield Co
•
Filing: 1986-08-07
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Granted: 1988-05-03
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Expires: 2006-08-07
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Abstract

Abstract In an improved method for inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from said formation, said method including injecting at least one scale inhibitor into said formation through said well so that said scale inhibitor is thereafter slowly released from said formation to inhibit the formation of scale, the improvement comprising: injecting at least one polymeric material into said well in an amount effective to prolong said scale formation inhibition, said polymeric material having a composition different from said scale inhibitor and being a copolymer derived from at least one first monomer having a maleic moiety and at least one second monomer selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof.

Inventors

  • 👤 David R. Underdown

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 00:59
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/52; C09K8/528; Y; Y10; Y10S; Y10S166/00; Y10S166/902; Y10S507/00; Y10S507/927

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 136 words
In a method for inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from said formation, said method including injecting at least one scale inhibitor into said formation through said well so that said scale inhibitor is thereafter slowly released from said formation to inhibit the formation of scale, the improvement comprising: injecting at least one polymeric material into said well in an amount effective to prolong said scale formation inhibition, said polymeric material having a composition different from said scale inhibitor, a number average molecular weight in the range of about 6000 to about 25,000 and being a copolymer derived from at least one first maleic anhydride monomer and at least one second monomer selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof.
Claim 2
Dependent Claim 136 words
In a method for inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from said formation, said method including injecting at least one scale inhibitor into said formation through said well so that said scale inhibitor is thereafter slowly released from said formation to inhibit the formation of scale, the improvement comprising: injecting at least one polymeric material into said well in an amount effective to prolong said scale formation inhibition, said polymeric material having a composition different from said scale inhibitor, a number average molecular weight in the range of about 6000 to about 25,000 and being a copolymer derived from at least one first maleic anhydride monomer and at least one second monomer selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof.
Claim 3
Dependent Claim 14 words
The method of claim 1 wherein said scale inhibitor is a non-polymeric scale inhibitor.
Claim 4
Dependent Claim 37 words
The method of claim 1 wherein said copolymer is prepared by copolymerizing a combination comprising about 35 to about 65 mole percent of said first monomer and about 65 to 35 mole percent of said second monomer.
Claim 5
Dependent Claim 13 words
The method of claim 1 wherein said polymer is at least partially hydrolyzed.
Claim 6
Dependent Claim 14 words
The method of claim 1 wherein said non-polymeric scale inhibitor is an amine phosphonate.
Claim 7
Dependent Claim 14 words
The method of claim 5 wherein said amine phosphonate is diethyltriaminepenta (methylene phosphonic acid).
Claim 8
Dependent Claim 16 words
The method of claim 1 wherein said polymer is injected substantially simultaneously with said scale inhibitor.
Claim 9
Dependent Claim 21 words
The method of claim 1 wherein said polymer and said scale inhibitor are injected as an admixture in a aqueous medium.
Claim 10
Dependent Claim 21 words
The method of claim 1 wherein the amount of polymer injected is minor relative to the amount of scale inhibitor injected.
Claim 11
Dependent Claim 31 words
The method of claim 9 wherein the amount of polymer injected is in the range of about 3% to about 45% by weight of the total polymer and scale inhibitor injected.
Claim 12
Dependent Claim 138 words
In a method for inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from said formation, said method including injecting at least one scale inhibitor into said formation through said well so that said scale inhibitor is thereafter slowly released from said formation to inhibit the formation of scale, the improvement comprising: injecting at least one polymeric material into said well in an amount effective to prolong said scale formation inhibition, said polymeric material having a composition different from said scale inhibitor a number average molecular weight in the range of about 6,000 to about 25,000 and being a copolymer derived from at least one first monomer having a maleic moiety and at least one second monomer selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof.
Claim 13
Dependent Claim 138 words
In a method for inhibiting the formation of scale in a well penetrating a subterranean formation for the production of fluids from said formation, said method including injecting at least one scale inhibitor into said formation through said well so that said scale inhibitor is thereafter slowly released from said formation to inhibit the formation of scale, the improvement comprising: injecting at least one polymeric material into said well in an amount effective to prolong said scale formation inhibition, said polymeric material having a composition different from said scale inhibitor a number average molecular weight in the range of about 6,000 to about 25,000 and being a copolymer derived from at least one first monomer having a maleic moiety and at least one second monomer selected from the group consisting of acrylic acid, methacrylic acid and mixtures thereof.

References Cited (Backward Citations)

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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) 1991-05-03 1991-11-02 1992-05-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-05-03 1995-11-02 1996-05-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-05-03 1999-11-02 2000-05-03 $7700.00 Window Closed / Lapsed

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