Patent US2979454A successfully refreshed from Google Patents.
US2979454A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drilling mud
Assignee: Monsanto Chemicals Ltd
•
Filing: 1957-03-20
•
Granted: 1961-04-11
•
Expires: 1977-03-20
Abstract
No abstract record available.
Inventors
- 👤 Joseph E Fields
- 👤 John H Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:35
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
50 words
A DRILLING FLUID COMPRISING AN AQUEOUS SUSPENSION OF FINELY DIVIDED SOLID INORGANIC MATERIALS AND A SUFFICIENT AMOUNT OF A COPOLYMER OF ETHYLENE AND MALEIC ANHYDRIDE HAVING A SPECIFIC VISCOSITY BELOW A VALUE OF ABOUT 0.70 TO MAINTAIN THE VISCOSITY OF THE MUD LOW ENOUGH SO THAT IT CAN BE CIRCULATED.
Claim 2
Dependent Claim
50 words
A DRILLING FLUID COMPRISING AN AQUEOUS SUSPENSION OF FINELY DIVIDED SOLID INORGANIC MATERIALS AND A SUFFICIENT AMOUNT OF A COPOLYMER OF ETHYLENE AND MALEIC ANHYDRIDE HAVING A SPECIFIC VISCOSITY BELOW A VALUE OF ABOUT 0.70 TO MAINTAIN THE VISCOSITY OF THE MUD LOW ENOUGH SO THAT IT CAN BE CIRCULATED.
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) | 1964-04-10 | 1964-10-10 | 1965-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-10 | 1968-10-10 | 1969-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-10 | 1972-10-10 | 1973-04-11 | $7700.00 | Window Closed / Lapsed |