US4631137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Materials for use in drilling fluids
Assignee: Ciba Specialty Chemicals Water Treatments Ltd
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Filing: 1984-10-30
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Granted: 1986-12-23
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Expires: 2004-10-30
Abstract
Abstract Bentonites can be extended for use in drilling muds by addition of a novel polymer blend comprising a low molecular weight water soluble non-ionic or anionic polymer and a high molecular weight anionic polymer.
Inventors
- 👤 Brian Dymond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:44
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24; E; E21; E21B; E21B21/00; E21B21/003
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
140 words
A composition comprising a blend of (a) a low molecular weight, water soluble non-ionic or anionic polymer having a molecular weight of about 1,000 to about 20,000 and formed from 0 to 100% acrylamide and 100 to 0% anionic monomer selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, allyl sulfonate and 2-acrylamido-2-methyl propane sulphonic acid and (b) a high molecular weight, water soluble, polymer having molecular weight of at least about 1 million and formed from polymerisable monomers of which 0 to 70% by weight are acrylamide and 30 to 100% by weight are selected from acrylic acid, allyl sulphonate and 2-acrylamido-2-methyl propane sulphonic acid, said blend being substantially free of polymer of molecular weight 50,000 to 500,000, and wherein the weight ratio of low molecular weight polymer:high molecular weight polymer is about 10:1 to 1:5.
Claim 2
Dependent Claim
140 words
A composition comprising a blend of (a) a low molecular weight, water soluble non-ionic or anionic polymer having a molecular weight of about 1,000 to about 20,000 and formed from 0 to 100% acrylamide and 100 to 0% anionic monomer selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, allyl sulfonate and 2-acrylamido-2-methyl propane sulphonic acid and (b) a high molecular weight, water soluble, polymer having molecular weight of at least about 1 million and formed from polymerisable monomers of which 0 to 70% by weight are acrylamide and 30 to 100% by weight are selected from acrylic acid, allyl sulphonate and 2-acrylamido-2-methyl propane sulphonic acid, said blend being substantially free of polymer of molecular weight 50,000 to 500,000, and wherein the weight ratio of low molecular weight polymer:high molecular weight polymer is about 10:1 to 1:5.
Claim 3
Dependent Claim
23 words
A composition according to claim 1 in which the high molecular weight polymer and the low molecular weight polymers are both polyacrylic acid.
Claim 4
Dependent Claim
22 words
A composition according to claim 1 in which the molecular weight of the high molecular weight polymer is about 1,000,000 to 15,000,000.
Claim 5
Dependent Claim
24 words
A composition according to claim 1 in which the weight ratio low molecular weight polymer:high molecular weight polymer is from about 5:1 to 1:1.
Claim 6
Dependent Claim
45 words
A composition according to claim 1 in which said anionic monomer is acrylic acid and in which said high molecular weight polymer is formed from polymerisable monomers of which 0 to 70% by weight are acrylamide and 30 to 100% by weight are acrylic acid.
Claim 7
Dependent Claim
16 words
A composition according to claim 1 containing bentonite and an effective extending amount of the blend.
Claim 8
Dependent Claim
33 words
An extended bentonite suitable for use in drilling muds and containing a bentonite that does not comply with API Specification 13A and an effective extending amount of a composition according to claim 1.
Claim 9
Dependent Claim
12 words
A composition according to claim 7 that complies with API Specification 13A.
Claim 10
Dependent Claim
21 words
A composition according to claim 1 in the form of an aqueous drilling mud containing the polymer blend and bentonite-type clay.
Claim 11
Dependent Claim
27 words
An aqueous drilling mud containing a bentonite that does not comply with API Specification 13A and an effective extending amount of a composition according to claim 1.
Claim 12
Dependent Claim
32 words
An aqueous drilling mud according to claim 10 in which the low and high molecular weight polymers are each polymers formed of 70 to 100% acrylic acid and 0 to 30% acrylamide.
Claim 13
Dependent Claim
71 words
A composition comprising a blend of low molecular weight, water soluble polymer formed of 70-100% acrylic acid and 0-30% acrylamide having a molecular weight about 1,000 to about 20,000 and a high molecular weight, water soluble, polymer formed of 70-100% acrylic acid and 0-30% acrylamide having a molecular weight of at least about 1 million, wherein the weight ratio low molecular weight polymer:high molecular weight polymer is about 10:1 to 1:5.
Claim 14
Dependent Claim
71 words
A composition comprising a blend of low molecular weight, water soluble polymer formed of 70-100% acrylic acid and 0-30% acrylamide having a molecular weight about 1,000 to about 20,000 and a high molecular weight, water soluble, polymer formed of 70-100% acrylic acid and 0-30% acrylamide having a molecular weight of at least about 1 million, wherein the weight ratio low molecular weight polymer:high molecular weight polymer is about 10:1 to 1:5.
References Cited (Backward Citations)
US2718497A
Cited
US2702788A
Cited
US3081260A
Cited
US3220946A
Cited
US3558545A
Cited
US4118441A
Cited
US4128528A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-22 | 1990-06-23 | 1990-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-22 | 1994-06-23 | 1994-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-22 | 1998-06-23 | 1998-12-23 | $7700.00 | Window Closed / Lapsed |