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US4201679A
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Drilling fluid additive
Assignee: MI Drilling Fluids Co
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Filing: 1978-11-03
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Granted: 1980-05-06
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Expires: 1998-11-03
Abstract
Abstract Drilling fluid viscosifier which includes sepiolite and a partially hydrolyzed polyacrylamide polymer extender therefor.
Inventors
- 👤 Larry D. Barker
- 👤 James K. Bannerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:04
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
55 words
A drilling fluid viscosifier consisting essentially of sepiolite and a 20% to 80% hydrolyzed polyacrylamide polymer extender therefor, having the general formula (CH 2 CHCONH 2 ) x , where x ranges between about 5600 and 14,900, said extender being present in an amount between about 0.01 and 0.25 pounds per 15 pounds of sepiolite.
Claim 2
Dependent Claim
55 words
A drilling fluid viscosifier consisting essentially of sepiolite and a 20% to 80% hydrolyzed polyacrylamide polymer extender therefor, having the general formula (CH 2 CHCONH 2 ) x , where x ranges between about 5600 and 14,900, said extender being present in an amount between about 0.01 and 0.25 pounds per 15 pounds of sepiolite.
Claim 3
Dependent Claim
14 words
The viscosifier of claim 1, which contains, in addition, an inert substrate, calcined kaolinite.
Claim 4
Dependent Claim
20 words
The viscosifier of claim 2, in which the inert substrate is present in an amount between about 15% and 35%.
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) | 1983-05-06 | 1983-11-05 | 1984-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-05-06 | 1987-11-05 | 1988-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-05-06 | 1991-11-05 | 1992-05-06 | $7700.00 | Window Closed / Lapsed |