Patent US3294681A successfully refreshed from Google Patents.
US3294681A
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Process of drilling a well with a drilling fluid containing a starch product
Assignee: NL Industries Inc
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Filing: 1965-10-21
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Granted: 1966-12-27
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Expires: 1985-10-21
Abstract
No abstract record available.
Inventors
- 👤 Robert O Stearns
- 👤 Donald J Weintritt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:10
CPC Classifications
C; C08; C08B; C08B31/00; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/20; C09K8/206
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
82 words
IN A PROCESS FOR DRILLING A WELL BY THE ROTARY METHOD WHEREIN A WATER-BASE DRILLING FLUID IS CIRCULATED IN SAID WELL, THE METHOD OF CONTROLLING THE FORMATION OF A FILTER CAKE ON THE WALL OF SAID WELL WHICH COMPRISES ADMIXING WITH SAID DRILLING FLUID AND INTERACTING THEREWITH A GELATINIZED STARCHY FLOUR PRODUCT WHICH HAS BEEN PRODUCED BY COMBINING A MOIST STARCH FLOUR CONTAINING FROM 1% TO 5% BY WEIGHT OF PARAFORMALDEHYDE AND FROM 1% TO 5% OF A COMPOUND HAVING THE FORMULA:
Claim 2
Dependent Claim
82 words
IN A PROCESS FOR DRILLING A WELL BY THE ROTARY METHOD WHEREIN A WATER-BASE DRILLING FLUID IS CIRCULATED IN SAID WELL, THE METHOD OF CONTROLLING THE FORMATION OF A FILTER CAKE ON THE WALL OF SAID WELL WHICH COMPRISES ADMIXING WITH SAID DRILLING FLUID AND INTERACTING THEREWITH A GELATINIZED STARCHY FLOUR PRODUCT WHICH HAS BEEN PRODUCED BY COMBINING A MOIST STARCH FLOUR CONTAINING FROM 1% TO 5% BY WEIGHT OF PARAFORMALDEHYDE AND FROM 1% TO 5% OF A COMPOUND HAVING THE FORMULA:
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) | 1969-12-26 | 1970-06-27 | 1970-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-12-26 | 1974-06-27 | 1974-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-12-26 | 1978-06-27 | 1978-12-27 | $7700.00 | Window Closed / Lapsed |