US3872018A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water loss additive for sea water mud comprising an alkaline earth oxide or hydroxide, starch and polyvinyl alcohol
Assignee: Hughes Tool Co
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Filing: 1972-11-15
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Granted: 1975-03-18
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Expires: 1992-11-15
Abstract
Abstract Fluid loss control at temperatures over 300* F in clay-free sea water muds of the type containing alkaline earth oxides, hydroxides and salts in a brine solution and using starch as a fluid loss control agent is improved by addition of polyvinyl alcohol with the starch. Urea with the polyvinyl alcohol further increases temperature stability of the systems.
Inventors
- 👤 Albert H D Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:22
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/06; C09K8/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
49 words
AN AQUEOUS CLAY-FREE DRILLING FLUID COMPRISING AN ALKALINE EARTH OXIDE OR HYDROXIDE DISSOLVED IN A BRINE SOLUTION AND INCLUDING STARCH AS A FLUID LOSS CONTROL AGENT, THE IMPROVEMENT WHEREIN SAID COMPOSITION CONTAINS A SMALL AMOUNT OF POLYVINYL ALCOHOL POLYMER SUFFICIENT TO MAINTAIN DESIRABLE FLUID LOSS PROPERTIES AT ELEVATED TEMPERATURES.
Claim 2
Dependent Claim
49 words
AN AQUEOUS CLAY-FREE DRILLING FLUID COMPRISING AN ALKALINE EARTH OXIDE OR HYDROXIDE DISSOLVED IN A BRINE SOLUTION AND INCLUDING STARCH AS A FLUID LOSS CONTROL AGENT, THE IMPROVEMENT WHEREIN SAID COMPOSITION CONTAINS A SMALL AMOUNT OF POLYVINYL ALCOHOL POLYMER SUFFICIENT TO MAINTAIN DESIRABLE FLUID LOSS PROPERTIES AT ELEVATED TEMPERATURES.
Claim 3
Dependent Claim
15 words
The drilling fluid of claim 1 wherein said polyvinyl alcohol is a high viscosity polymer.
Claim 4
Dependent Claim
18 words
The drilling fluid of claim 2 containing 2 to 10 pounds of said polyvinyl alcohol polymer per barrel.
Claim 5
Dependent Claim
24 words
The drilling fluid of claim 2 including from 1 to 10 parts by weight urea to 10 parts by weight of said polyvinyl alcohol.
Claim 6
Dependent Claim
15 words
The drilling fluid of claim 2 wherein said polyvinyl alcohol is at least 85% alcoholized.
Claim 7
Dependent Claim
66 words
An aqueous clay-free drilling fluid comprising a member selected from the group consisting of of calcium oxide, mangesium oxide and magnesium hydroxide, at least one additional magnesium compound selected from the group of magnesium chloride and magnesium carbonate in a brine solution and containing starch as a fluid loss agent and an amount of polyvinyl alcohol sufficient to maintain desirable fluid loss properties at high temperatures.
Claim 8
Dependent Claim
66 words
An aqueous clay-free drilling fluid comprising a member selected from the group consisting of of calcium oxide, mangesium oxide and magnesium hydroxide, at least one additional magnesium compound selected from the group of magnesium chloride and magnesium carbonate in a brine solution and containing starch as a fluid loss agent and an amount of polyvinyl alcohol sufficient to maintain desirable fluid loss properties at high temperatures.
Claim 9
Dependent Claim
39 words
The drilling fluid of claim 6 wherein said starch is present in an amount of from about 10 to 30 pounds per barrel and said polyvinyl alcohol is present in amounts of 2 to about 10 pounds per barrel.
Claim 10
Dependent Claim
22 words
The drilling fluid of claim 6 wherein said polyvinyl alcohol is a high viscosity polymer which is at least 85 percent alcoholized.
Claim 11
Dependent Claim
24 words
The drilling fluid of claim 6 including from 1 to 10 parts by weight urea per 10 parts by weight of said polyvinyl alcohol.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |