US4675119A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aqueous drilling and packer fluids
Assignee: Ciba Specialty Chemicals Water Treatments Ltd
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Filing: 1985-08-02
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Granted: 1987-06-23
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Expires: 2005-08-02
Abstract
Abstract Sulphonated polymers and copolymers are used as thinners in aqueous drilling or packer fluids. The sulphonated polymer has polydispersity below 2 and has a low solution viscosity. It is generally a copolymer of beta-acrylamidoalkane sulphonate or allyl sulphonate or other aliphatic sulphonate with an ethylenically unsaturated carboxylic acid, generally acrylic acid.
Inventors
- 👤 David Farrar
- 👤 Brian Dymond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:28
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24; Y; Y10; Y10S; Y10S507/00; Y10S507/92; Y10S507/926
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
112 words
An aqueous fluid selected from drilling and packer fluids and containing, as thinner, an effective thinning amount of a water soluble polymer that has a viscosity of below 300 cps (Brookfield Viscometer, Model RVT, Spindle No. 1, speed 20 rpm, 15% by weight active polymer solution at 20° C.) and a polydispersity below 2.0 and that is formed from (a) 10 to 60% by weight 2-acrylamido-2-methyl propane sulphonic acid and (b) 40 to 90% by weight acrylic acid, wherein the acid groups are selected from free acid groups and ammonium and alkali metal salts thereof, and having a molecular weight of 1,000 to 8,000, said fluid 25 to 150 g/l colloidal clay
Claim 2
Dependent Claim
112 words
An aqueous fluid selected from drilling and packer fluids and containing, as thinner, an effective thinning amount of a water soluble polymer that has a viscosity of below 300 cps (Brookfield Viscometer, Model RVT, Spindle No. 1, speed 20 rpm, 15% by weight active polymer solution at 20° C.) and a polydispersity below 2.0 and that is formed from (a) 10 to 60% by weight 2-acrylamido-2-methyl propane sulphonic acid and (b) 40 to 90% by weight acrylic acid, wherein the acid groups are selected from free acid groups and ammonium and alkali metal salts thereof, and having a molecular weight of 1,000 to 8,000, said fluid 25 to 150 g/l colloidal clay
Claim 3
Dependent Claim
15 words
A fluid according to claim 1 in which the polymer has a polydispersity below 1.8.
Claim 4
Dependent Claim
16 words
A fluid according to claim 1 in which the polymer has a molecular weight below 6,000.
Claim 5
Dependent Claim
15 words
A fluid according to claim 1 in which the polymer has a polydispersity below 1.6.
Claim 6
Dependent Claim
29 words
A fluid according to claim 1 in which the amount of (a) is 10 to 25% by weight and the amount of (b) is 75 to 90% by weight.
Claim 7
Dependent Claim
42 words
A fluid according to claim 1 in which the copolymer has a molecular weight of 1,000 to 6,000, and is a copolymer of 10 to 45% by weight of 2-acrylamido-2-methyl-propane sulphonic acid, sodium salt and 55 to 90% by weight sodium acrylate.
Claim 8
Dependent Claim
13 words
A fluid according to claim 1 containing at least 0.25 g/l dissolved calcium.
Claim 9
Dependent Claim
41 words
A fluid according to claim 1 in which the polymer is formed from 18 to 22% by weight 2-acrylamido-2-methyl propane sulphonic acid sodium salt and 78 to 82% by weight sodium acrylate and has a molecular weight of 2,000 to 4,500.
Claim 10
Dependent Claim
19 words
A fluid according to claim 1 in which the amount of said thinner is from 0.15 to 30 g/l.
Claim 11
Dependent Claim
14 words
A fluid according to claim 1 in which said viscosity is below 50 cps.
Claim 12
Dependent Claim
29 words
A fluid according to claim 1 further including inorganic particulate selected from the group consisting of drilled rock particles and 100 to 1000 g/l weighting agent and combinations thereof.
Claim 13
Dependent Claim
92 words
An aqueous fluid selected from drilling and packer fluids and containing 25 to 150 g/l colloidal clay and, as thinner, an effective thinning amount of a water soluble polymer that has a viscosity below 300 cps (Brookfield Viscometer, Model RVT, Spindle No. 1, speed 20 rpm, 15% by weight active polymer solution at 20° C.) and a polydispersity below 2 and a molecular weight from 2000 to 4500 and that is formed from 15 to 25% by weight 2-acrylamido-2-methyl propane sulphonic acid sodium salt and 85 to 75% by weight sodium acrylate.
Claim 14
Dependent Claim
92 words
An aqueous fluid selected from drilling and packer fluids and containing 25 to 150 g/l colloidal clay and, as thinner, an effective thinning amount of a water soluble polymer that has a viscosity below 300 cps (Brookfield Viscometer, Model RVT, Spindle No. 1, speed 20 rpm, 15% by weight active polymer solution at 20° C.) and a polydispersity below 2 and a molecular weight from 2000 to 4500 and that is formed from 15 to 25% by weight 2-acrylamido-2-methyl propane sulphonic acid sodium salt and 85 to 75% by weight sodium acrylate.
Claim 15
Dependent Claim
15 words
A fluid according to claim 12 in which the polymer has a polydispersity below 1.8.
Claim 16
Dependent Claim
17 words
A fluid according to claim 13 in which the polymer has a polydispersity from 1.35 to 1.6.
Claim 17
Dependent Claim
21 words
A fluid according to claim 14 in which the amount of 2-acrylamido-2-methyl propane sulphonic acid sodium salt is 20 weight %.
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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) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |