Patent US4374738A successfully refreshed from Google Patents.
US4374738A
Expired / Lapsed
US
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Drilling fluid composition
Assignee: Georgia-Pacific LLC
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Filing: 1981-09-21
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Granted: 1983-02-22
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Expires: 2001-09-21
Abstract
Abstract A water-based drilling fluid composition is described which comprises an aqueous dispersion of a clay material containing an effective dispersing amount of a modified lignosulfonate which is obtained by graft polymerization of from 5 to 30 weight percent of an acrylic compound with the lignosulfonate. The grafted lignosulfonate has an average molecular weight of less than 80,000.
Inventors
- 👤 Jack R. Kelley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:29
CPC Classifications
C; C08; C08F; C08F289/00; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
94 words
A water-base drilling fluid comprising a suspension of clay material and an effective dispersing amount of a water-soluble graft copolymer which is the reaction product of lignosulfonate and an acrylic compound selected from the group consisting of acrylic acid, acrylonitrile, acrylamide, and esters of alcohols of one or two carbon atoms and acrylic acid, said reaction product being prepared by reacting lignosulfonate with from 5 to 30 weight percent said acrylic compound at a pH below 6 using a free radical initiator, said reaction product having an average molecular weight not exceeding about 80,000.
Claim 2
Dependent Claim
94 words
A water-base drilling fluid comprising a suspension of clay material and an effective dispersing amount of a water-soluble graft copolymer which is the reaction product of lignosulfonate and an acrylic compound selected from the group consisting of acrylic acid, acrylonitrile, acrylamide, and esters of alcohols of one or two carbon atoms and acrylic acid, said reaction product being prepared by reacting lignosulfonate with from 5 to 30 weight percent said acrylic compound at a pH below 6 using a free radical initiator, said reaction product having an average molecular weight not exceeding about 80,000.
Claim 3
Dependent Claim
16 words
A composition according to claim 1 wherein the water-base drilling fluid is a seawater drilling fluid.
Claim 4
Dependent Claim
11 words
A composition of claim 1 wherein the acrylic compound is acrylamide.
Claim 5
Dependent Claim
12 words
A process according to claim 1 wherein the acrylic compound is acrylonitrile.
Claim 6
Dependent Claim
13 words
A composition according to claim 1 wherein the acrylic compound is acrylic acid.
Claim 7
Dependent Claim
24 words
A composition according to claim 5 wherein the acrylic acid is reacted with the lignosulfonate in an amount of from 10 to 15 percent.
Claim 8
Dependent Claim
31 words
A composition according to claim 1 wherein the lignosulfonate is reacted with the acrylic compound until said reaction product has an average molecular weight in the range of 20,000 to 60,000.
Claim 9
Dependent Claim
12 words
A composition according to claim 7 wherein the acrylic compound is acrylonitrile.
Claim 10
Dependent Claim
12 words
A composition according to claim 7 wherein the acrylic compound is acrylamide.
Claim 11
Dependent Claim
13 words
A composition according to claim 7 wherein the acrylic compound is acrylic acid.
Claim 12
Dependent Claim
16 words
A composition according to claim 10 wherein the water-base drilling fluid is a seawater drilling fluid.
Claim 13
Dependent Claim
16 words
A composition according to claim 10 wherein the reaction product is essentially an alkali metal salt.
Claim 14
Dependent Claim
15 words
A composition according to claim 12 wherein the reaction product is essentially a sodium salt.
Claim 15
Dependent Claim
15 words
A composition according to claim 12 wherein the reaction product is essentially a potassium salt.
Claim 16
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 17
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 18
Dependent Claim
20 words
A process of drilling a well comprising circulating in the well, while drilling, a drilling fluid composition of claim 6.
Claim 19
Dependent Claim
26 words
A process of drilling a well comprising circulating in the well, while drilling, at a temperature above 250° F., a drilling fluid composition of claim 1.
Claim 20
Dependent Claim
26 words
A process of drilling a well comprising circulating in the well, while drilling, at a temperature above 250° F., a drilling fluid composition of claim 12.
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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) | 1986-02-21 | 1986-08-23 | 1987-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-21 | 1990-08-23 | 1991-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-21 | 1994-08-23 | 1995-02-22 | $7700.00 | Window Closed / Lapsed |