US4425241A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drilling fluids
Assignee: Drilling Specialties Co
•
Filing: 1981-12-16
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Granted: 1984-01-10
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Expires: 2001-12-16
Abstract
Abstract Polyethylene glycols in combination with at least one water-dispersible polymeric viscosifier comprising cellulose ethers, cellulose sulfate esters, polyacrylamides, guar gum, or heteropolysaccharides improve the water loss properties of water-based drilling fluids, particularly in hard brine environments.
Inventors
- 👤 Billy L. Swanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:33
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/58; C09K8/588; C08; C08L; C08L71/00; C08L71/02; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/20; C09K8/206; C09K8/22; C09K8/50
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
141 words
A water-based drilling mud composition comprising in combination (a) sufficient aqueous solution of mineral salts having greater than 10,000 ppm dissolved solids content to maintain the mud as a fluid, (b) sufficient clayey material to form a filter cake on the wall of a well, (c) at least one water dispersible polymeric viscosifier selected from the group consisting of carboxyalkyl hydroxyalkyl cellulose ethers, carboxyalkyl cellulose ethers, hydroxyalkyl cellulose ethers, polyacrylamides, cellulose sulfate esters, guar gum, and heteropolysaccharides produced by fermentation of carbohydrates by bacteria of the genus Xanthomonas, and (d) a polyethylene glycol component having a molecular weight ranging from about 6,000 to about 20,000 wherein the weight ratio of (c) to (d) ranges from about 3:1 to about 1:3, and the combined amount of (c) and (d) being sufficient to reduce water loss due to filtration through said filter cake.
Claim 2
Dependent Claim
141 words
A water-based drilling mud composition comprising in combination (a) sufficient aqueous solution of mineral salts having greater than 10,000 ppm dissolved solids content to maintain the mud as a fluid, (b) sufficient clayey material to form a filter cake on the wall of a well, (c) at least one water dispersible polymeric viscosifier selected from the group consisting of carboxyalkyl hydroxyalkyl cellulose ethers, carboxyalkyl cellulose ethers, hydroxyalkyl cellulose ethers, polyacrylamides, cellulose sulfate esters, guar gum, and heteropolysaccharides produced by fermentation of carbohydrates by bacteria of the genus Xanthomonas, and (d) a polyethylene glycol component having a molecular weight ranging from about 6,000 to about 20,000 wherein the weight ratio of (c) to (d) ranges from about 3:1 to about 1:3, and the combined amount of (c) and (d) being sufficient to reduce water loss due to filtration through said filter cake.
Claim 3
Dependent Claim
23 words
The drilling mud of claim 1 wherein said amount is in the range of about 0.25 to about 3 lbs/bbl of said mud.
Claim 4
Dependent Claim
29 words
A drilling mud according to claim 1 wherein (c) is a cellulose ether selected from the group consisting of carboxymethylhydroxyethyl cellulose (CMHEC), carboxymethyl cellulose (CMC), and hydroxyethyl cellulose (HEC).
Claim 5
Dependent Claim
12 words
A drilling mud according to claim 1 wherein (c) is guar gum.
Claim 6
Dependent Claim
12 words
A drilling mud according to claim 1 wherein (c) is cellulose sulfate.
Claim 7
Dependent Claim
28 words
A drilling mud according to claim 1 wherein (c) is (1) a mixture of a polyacrylamide and guar gum or (2) a mixture of polyacrylamide and a heteropolysaccharide.
Claim 8
Dependent Claim
23 words
A drilling mud according to claim 1 wherein (c) is a heteropolysaccharide produced by fermentation of carbohydrates by bacteria of the genus Xanthomonas.
Claim 9
Dependent Claim
38 words
A drilling mud according to claim 1 wherein the total amount of (c) and (d) present ranges from about 0.75 to about 2.0 lb/bbl of mud and wherein the weight ratio of (c) to (d) is about 1:1.
Claim 10
Dependent Claim
29 words
A composition according to claim 1 which is a brine containing from about 0.75 to about 2.0 lbs of a mixture of (c) and (d) per barrel of mud.
Claim 11
Dependent Claim
16 words
A composition according to claim 9 wherein there are approximately equal weights of (c) and (d).
Claim 12
Dependent Claim
39 words
In a method of drilling a well with drilling tools, the steps of circulating through the well during said drilling, a water-based drilling mud according to claim 1 which forms a filter cake on the wall of said well.
Claim 13
Dependent Claim
29 words
The method of claim 11 wherein the amount of (c) plus (d) in said mud is in the range of about 0.25 to about 3 lb/bbl of said mud.
Claim 14
Dependent Claim
28 words
The method of claim 11 wherein the amount of (c) plus (d) in said mud is in the range of about 0.75 to about 2.0 lbs/bbl of mud.
Claim 15
Dependent Claim
20 words
The method according to claim 12 wherein there are about equal weights of (c) and (d) present in said mud.
Claim 16
Independent Claim
163 words
A method for preparing an aqueous drilling fluid composition containing clay, mineral salts dissolved in said fluid composition to provide greater than 10,000 ppm dissolved solids content and, optionally, weighting, suspending and conditioning agents exhibiting improved rheological properties which comprises incorporating therein (a) a first-water dispersible polymeric viscosifier selected from the group consisting of carboxyalkyl hydroxyalkyl cellulose ethers, carboxyalkyl cellulose ethers, hydroxyalkyl cellulose ethers, polyacrylamides, cellulose sulfate esters, guar gum, and heteropolysaccharides produced by fermentation of carbohydrates by bacteria of the genus Xanthomonas, and (b) a polyethylene glycol having a molecular weight ranging from about 6,000 to about 20,000 in a weight ratio of (a) to (b) ranging from about 3:1 to about 1:3, the combined amount of (a) and (b) being sufficient to reduce water loss of said drilling fluid composition and (c) adding a yield point improving amount of a second polymer selected from said polymeric viscosifiers which is different from the first polymeric viscosifier incorporated into said drilling fluid composition.
Claim 17
Independent Claim
163 words
A method for preparing an aqueous drilling fluid composition containing clay, mineral salts dissolved in said fluid composition to provide greater than 10,000 ppm dissolved solids content and, optionally, weighting, suspending and conditioning agents exhibiting improved rheological properties which comprises incorporating therein (a) a first-water dispersible polymeric viscosifier selected from the group consisting of carboxyalkyl hydroxyalkyl cellulose ethers, carboxyalkyl cellulose ethers, hydroxyalkyl cellulose ethers, polyacrylamides, cellulose sulfate esters, guar gum, and heteropolysaccharides produced by fermentation of carbohydrates by bacteria of the genus Xanthomonas, and (b) a polyethylene glycol having a molecular weight ranging from about 6,000 to about 20,000 in a weight ratio of (a) to (b) ranging from about 3:1 to about 1:3, the combined amount of (a) and (b) being sufficient to reduce water loss of said drilling fluid composition and (c) adding a yield point improving amount of a second polymer selected from said polymeric viscosifiers which is different from the first polymeric viscosifier incorporated into said drilling fluid composition.
Claim 18
Dependent Claim
35 words
A method according to claim 15 wherein the amount of the second polymeric viscosifier is sufficient to provide a total weight ratio of polymeric viscosifiers to polyethylene glycol ranging from about 3:1 to about 1:3.
Claim 19
Dependent Claim
28 words
A method according to claim 16 wherein said first polymeric viscosifier is carboxymethyl hydroxyethyl cellulose, carboxymethyl cellulose or hydroxyethyl cellulose and said second polymeric viscosifier is guar gum.
Claim 20
Dependent Claim
15 words
A method according to claim 17 wherein said first polymeric viscosifier is carboxymethyl hydroxyethyl cellulose.
Claim 21
Dependent Claim
28 words
A method according to claim 16 wherein said first polymeric viscosifier is carboxymethyl hydroxyethyl cellulose, carboxymethyl cellulose or hydroxyethyl cellulose and said second polymeric viscosifier is a heteropolysaccharide.
Claim 22
Dependent Claim
15 words
A method according to claim 19 wherein said first polymeric viscosifier is carboxymethyl hydroxyethyl cellulose.
Claim 23
Dependent Claim
30 words
A method according to claim 17 wherein said (a) and (b) is about a 50:50 mixture of carboxymethyl hydroxyethyl cellulose and polyethylene glycol having a molecular weight of about 8,000.
Claim 24
Dependent Claim
30 words
A method according to claim 18 wherein said (a) and (b) is about a 50:50 mixture of carboxymethyl hydroxyethyl cellulose and polyethylene glycol having a molecular weight of about 8,000.
References Cited (Backward Citations)
US2425768A
Cited
US2618595A
Cited
US2775557A
Cited
US2854407A
Cited
US3198268A
Cited
DE1645283C3
Cited
US3525688A
Cited
US3516496A
Cited
US3613790A
Cited
US4141746A
Cited
US3779914A
Cited
US3836465A
Cited
US3747681A
Cited
US3818998A
Cited
US3989630A
Cited
US3993551A
Cited
US4005749A
Cited
US4172800A
Cited
GB1591313A
Cited
US4239629A
Cited
GB2036055B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |