Patent US3332872A successfully refreshed from Google Patents.
US3332872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drilling fluid
Assignee: Monsanto Co
•
Filing: 1962-12-28
•
Granted: 1967-07-25
•
Expires: 1982-12-28
Abstract
No abstract record available.
Inventors
- 👤 David T Oakes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:07
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
53 words
A DRILLING FLUID COMPRISING AN AQUEOUS SUSPENSION OF FINELY DIVIDED SOLID INORGANIC MATERIALS AND A SUFFICIENT AMOUNT OF A COPOLYMER OF STYRENE AND MALEIC ANHYDRIDE HAVING A SPECIFIC VISCOSITY IN THE RANGE FROM ABOUT 0.01 TO ABOUT 0.3 TO MAINTAIN THE VISCOSITY OF THE MUD LOW ENOUGH SO THAT IT CAN BE CIRCULATED.
Claim 2
Dependent Claim
53 words
A DRILLING FLUID COMPRISING AN AQUEOUS SUSPENSION OF FINELY DIVIDED SOLID INORGANIC MATERIALS AND A SUFFICIENT AMOUNT OF A COPOLYMER OF STYRENE AND MALEIC ANHYDRIDE HAVING A SPECIFIC VISCOSITY IN THE RANGE FROM ABOUT 0.01 TO ABOUT 0.3 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) | 1970-07-24 | 1971-01-23 | 1971-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-07-24 | 1975-01-23 | 1975-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-07-24 | 1979-01-23 | 1979-07-25 | $7700.00 | Window Closed / Lapsed |