Patent US4726906A successfully refreshed from Google Patents.
US4726906A
Expired / Lapsed
US
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Polymers for use as filtration control aids in drilling muds
Assignee: ECC SPECIALTY CHEMICALS Inc
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Filing: 1986-12-04
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Granted: 1988-02-23
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Expires: 2006-12-04
Abstract
Abstract The instant invention is directed to a polymer, having an intrinsic viscosity of 1.0 to 7.0, preferably 1.5 to 5.0, dl/g in 1.0 M NaCl, prepared from: (A) 2.5 to 45%, by weight, of at least one unsaturated carboxylic acid, or its salt; (B) 5.0 to 85%, by weight, of at least one unsaturated sulfonic acid, or its salt; (C) 2.5 to 15%, by weight, of at least one unsaturated cationic-containing monomer; and (D) 0 to 90%, by weight, of at least one unsaturated non-ionic monomer. The instant invention is also directed to the polymer in combination with an aqueous clay dispersion and the use of the admixture as a filtration aid in drilling muds.
Inventors
- 👤 Shih-Ruey T. Chen
- 👤 Christine A. Costello
- 👤 Gary F. Matz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:25
CPC Classifications
C; C08; C08F; C08F228/00; C08F220/00; C08F220/02; C08F220/04; C08F246/00; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
137 words
An aqueous drilling fluid comprising: (i) an aqueous clay dispersion; and (ii) a polymer, having an intrinsic viscosity of 1.0 to 7.0 dl/g in 1.0 M NaCl, prepared from: (A) 25 to 35%, by weight, of at least one unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid and their salts; (B) 25 to 40%, by weight, of at least one unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-methylpropyl sulfonic acid, and their salts; (C) 5 to 10%, by weight, of at least one unsaturated cationic containing monomer selected from the group consisting of dimethyldiallyl ammonium chloride, dimethyldiallyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride; and (D) 15 to 45%, by weight, of at least one unsaturated non-ionic monomer selected from the group consisting of acrylamide and methacrylamide.
Claim 2
Dependent Claim
137 words
An aqueous drilling fluid comprising: (i) an aqueous clay dispersion; and (ii) a polymer, having an intrinsic viscosity of 1.0 to 7.0 dl/g in 1.0 M NaCl, prepared from: (A) 25 to 35%, by weight, of at least one unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid and their salts; (B) 25 to 40%, by weight, of at least one unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-methylpropyl sulfonic acid, and their salts; (C) 5 to 10%, by weight, of at least one unsaturated cationic containing monomer selected from the group consisting of dimethyldiallyl ammonium chloride, dimethyldiallyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride; and (D) 15 to 45%, by weight, of at least one unsaturated non-ionic monomer selected from the group consisting of acrylamide and methacrylamide.
Claim 3
Dependent Claim
23 words
The aqueous drilling fluid of claim 1, wherein said polymer has an intrinsic viscosity of 1.5 to 5.0 dl/g in 1.0 M NaCl.
Claim 4
Independent Claim
161 words
A method for drilling a well in a subterranean formation, comprising circulating into the well, during drilling, an aqueous drilling fluid, the improvement wherein said aqueous drilling fluid comprises: (i) an aqueous clay dispersion; and (ii) a polymer, having an intrinsic viscosity of 1.0 to 7.0 dl/g in 1.0 M NaCl, prepared from: (A) 25 to 35%, by weight, of at least one unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid and their salts; (B) 25 to 40%, by weight, of at least one unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-methylpropyl sulfonic acid, and their salts; (C) 5 to 10%, by weight, of at least one unsaturated cationic containing monomer selected from the group consisting of dimethyldiallyl ammonium chloride, dimethyldiallyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride; and (D) 15 to 45%, by weight, of at least one unsaturated non-ionic monomer selected from the group consisting of acrylamide and methacrylamide.
Claim 5
Independent Claim
161 words
A method for drilling a well in a subterranean formation, comprising circulating into the well, during drilling, an aqueous drilling fluid, the improvement wherein said aqueous drilling fluid comprises: (i) an aqueous clay dispersion; and (ii) a polymer, having an intrinsic viscosity of 1.0 to 7.0 dl/g in 1.0 M NaCl, prepared from: (A) 25 to 35%, by weight, of at least one unsaturated carboxylic acid selected from the group consisting of acrylic acid, methacrylic acid and their salts; (B) 25 to 40%, by weight, of at least one unsaturated sulfonic acid selected from the group consisting of 2-acrylamido-2-methylpropyl sulfonic acid, 2-methacrylamido-2-methylpropyl sulfonic acid, and their salts; (C) 5 to 10%, by weight, of at least one unsaturated cationic containing monomer selected from the group consisting of dimethyldiallyl ammonium chloride, dimethyldiallyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride; and (D) 15 to 45%, by weight, of at least one unsaturated non-ionic monomer selected from the group consisting of acrylamide and methacrylamide.
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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) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |