US3338320A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Clear water drilling fluid
Assignee: Dow Chemical Co
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Filing: 1964-08-03
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Granted: 1967-08-29
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Expires: 1984-08-03
Abstract
No abstract record available.
Inventors
- 👤 James R Gilson
- 👤 Robert J Schallenkamp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:58
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/06; C09K8/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
95 words
IN A METHOD OF DRILLING A W ELL INTO A S UBTERRNEAN FORMATION EMPLOYING A POWER-DRIVEN CUTTING BIT AND A CLEAR WATER DRILLING FLUID, THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF ADMIXING WITH SAID DRILLING FLUID BETWEEN 0.0001 AND 1.0 PERCENT OF A WATER-SOLUBLE SALT OF POLYMETHACRYLIC ACID AND BETWEEN 0.001 AND 1.0 PERCENT OF WATER SOLUBLE POLYACRYLAMIDE, HAVING A MOLECULAR WEIGHT OF BETWEEN ABOUT 100,000 AND 3,000,000 CONTAINING UP TO 60% OF THE CARBOXOAMIDE GROUPS HYDROLYZED, AND CIRCULATING THE RESULTING SO-TREATED DRILLING FLUID DOWN THE WELLBORE, THROUGH THE BIT, AND UP TO THE EARTH''S SURFACE.
Claim 2
Dependent Claim
95 words
IN A METHOD OF DRILLING A W ELL INTO A S UBTERRNEAN FORMATION EMPLOYING A POWER-DRIVEN CUTTING BIT AND A CLEAR WATER DRILLING FLUID, THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF ADMIXING WITH SAID DRILLING FLUID BETWEEN 0.0001 AND 1.0 PERCENT OF A WATER-SOLUBLE SALT OF POLYMETHACRYLIC ACID AND BETWEEN 0.001 AND 1.0 PERCENT OF WATER SOLUBLE POLYACRYLAMIDE, HAVING A MOLECULAR WEIGHT OF BETWEEN ABOUT 100,000 AND 3,000,000 CONTAINING UP TO 60% OF THE CARBOXOAMIDE GROUPS HYDROLYZED, AND CIRCULATING THE RESULTING SO-TREATED DRILLING FLUID DOWN THE WELLBORE, THROUGH THE BIT, AND UP TO THE EARTH''S SURFACE.
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) | 1970-08-28 | 1971-02-27 | 1971-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-08-28 | 1975-02-27 | 1975-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-08-28 | 1979-02-27 | 1979-08-29 | $7700.00 | Window Closed / Lapsed |