Patent US3985659A successfully refreshed from Google Patents.
US3985659A
Expired / Lapsed
US
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Drilling fluid composition
Assignee: Georgia-Pacific LLC
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Filing: 1975-02-24
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Granted: 1976-10-12
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Expires: 1995-02-24
Abstract
Abstract An aqueous drilling fluid comprising bentonite, or subbentonite and a water-soluble copolymer of lignosulfonate and a polyacrylate in a sufficient amount to increase the yield of the clay.
Inventors
- 👤 Vincent F. Felicetta
- 👤 Donald E. Wenzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:58
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
76 words
An aqueous, low-solids drilling fluid composition comprising water, bentonite or subbentonite clay and a water-soluble graft copolymer of lignosulfonate and a polyacrylate in a sufficient amount to increase the yield of the clay, said copolymer being prepared by polymerization of the acrylate monomer with the lignosulfonate in a weight ratio of 2:1 to 1:5 of the acrylate monomer to lignosulfonate using a free radical initiator and said copolymer having a molecular weight of at least 100,000.
Claim 2
Dependent Claim
76 words
An aqueous, low-solids drilling fluid composition comprising water, bentonite or subbentonite clay and a water-soluble graft copolymer of lignosulfonate and a polyacrylate in a sufficient amount to increase the yield of the clay, said copolymer being prepared by polymerization of the acrylate monomer with the lignosulfonate in a weight ratio of 2:1 to 1:5 of the acrylate monomer to lignosulfonate using a free radical initiator and said copolymer having a molecular weight of at least 100,000.
Claim 3
Dependent Claim
11 words
A composition of claim 1 wherein the polyacrylate is acrylic acid.
Claim 4
Dependent Claim
27 words
A composition of claim 2 wherein the lignosulfonate polyacrylate copolymer is present in the drilling fluid in an amount of from 0.01 to 1 pound per barrel.
Claim 5
Dependent Claim
41 words
A composition according to claim 2 wherein the acrylic acid and lignosulfonate are copolymerized to an extent that the intrinsic viscosity of the reaction mixture is at least 1.0 dlg.sup. -1 in 0.1 M sodium chloride aqueous solution at 25° C.
Claim 6
Dependent Claim
25 words
A composition according to claim 4 wherein the intrinsic viscosity of the reaction mixture is in the range of 1.2 to 3.0 dlg.sup. -1 .
Claim 7
Dependent Claim
107 words
A composition according to claim 1 wherein the polyacrylate is a copolymer of acrylic acid and a monomer of a derivative of acrylic acid selected from the group consisting of methacrylic acid, acrylamide, alkyl esters of 1 to 2 carbon atoms of acrylic acid, and alkyl esters of 1 to 2 carbon atoms of methacrylic acids, said copolymer of polyacrylate and lignosulfonate being prepared by polymerization of acrylic acid and the acrylic acid derivative monomer with lignosulfonate using a free radical initiator, said acrylic acid being present in sufficient ratio to the acrylic acid derivative monomer to obtain a water soluble copolymer of lignosulfonate and the polyacrylate.
Claim 8
Dependent Claim
33 words
A composition of claim 6 wherein the acrylic acid derivative is acrylamide and is added in an amount of from 20 to 40 weight percent of the acrylic acid in the polymerization reaction.
Claim 9
Dependent Claim
20 words
A process of drilling a well comprising circulating in the well while drilling a drilling fluid composition of claim 1.
Claim 10
Dependent Claim
20 words
A process of drilling a well comprising circulating in the well while drilling a drilling fluid composition of claim 4.
Claim 11
Dependent Claim
20 words
A process of drilling a well comprising circulating in the well while drilling a drilling fluid composition of claim 5.
Claim 12
Dependent Claim
20 words
A process of drilling a well comprising circulating in the well while drilling a drilling fluid composition of claim 7.
References Cited (Backward Citations)
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Cited
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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) | 1979-10-12 | 1980-04-12 | 1980-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-12 | 1984-04-12 | 1984-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-12 | 1988-04-12 | 1988-10-12 | $7700.00 | Window Closed / Lapsed |