Patent US2469626A successfully refreshed from Google Patents.
US2911366A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drilling mud
Assignee: Monsanto Chemicals Ltd
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Filing: 1957-04-11
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Granted: 1959-11-03
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Expires: 1977-04-11
Abstract
No abstract record available.
Inventors
- 👤 Ross M Hedrick
- 👤 David T Mowry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:01
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/003
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
89 words
A DRILLING FLUID COMPRISING AN AQUEOUS SUSPENSION OF FINELY DIVIDED SOLID INORGANIC MATERIAL WHICH FORM A FILTER CAKE ON THE WALL OF A WELL AND A COPOLYMER OF AN OLEFIN CONTAINING FROM 1 TO 8 CARBON ATOMS AND MALEIC ANHYDRIDE HAVING A SPECIFIC VISOSITY ABOVE 0.70, SAID COPOLYMER BEING PRESENT IN THE FORM OF ITS HALF-AMIDE, HALF-AMMONIUM SALT AND IN AN AMOUNT SUFFICIENT TO REDUCE THE WATER LOSS DUE TO FILTRATION THROUGH SAID CAKE BUT INSUFFICIENT TO INCREASE THE VISCOSITY OF SAID DRILLING FLUID SUCH THAT IT BECOMES UNCIRCULATABLE.
Claim 2
Dependent Claim
89 words
A DRILLING FLUID COMPRISING AN AQUEOUS SUSPENSION OF FINELY DIVIDED SOLID INORGANIC MATERIAL WHICH FORM A FILTER CAKE ON THE WALL OF A WELL AND A COPOLYMER OF AN OLEFIN CONTAINING FROM 1 TO 8 CARBON ATOMS AND MALEIC ANHYDRIDE HAVING A SPECIFIC VISOSITY ABOVE 0.70, SAID COPOLYMER BEING PRESENT IN THE FORM OF ITS HALF-AMIDE, HALF-AMMONIUM SALT AND IN AN AMOUNT SUFFICIENT TO REDUCE THE WATER LOSS DUE TO FILTRATION THROUGH SAID CAKE BUT INSUFFICIENT TO INCREASE THE VISCOSITY OF SAID DRILLING FLUID SUCH THAT IT BECOMES UNCIRCULATABLE.
References Cited (Backward Citations)
US2718497A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-11-02 | 1963-05-04 | 1963-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-02 | 1967-05-04 | 1967-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-02 | 1971-05-04 | 1971-11-03 | $7700.00 | Window Closed / Lapsed |