Patent US2758196A successfully refreshed from Google Patents.
Patent US2640810A successfully refreshed from Google Patents.
US2640810A
Expired / Lapsed
US
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Treatment of wells
Assignee: Dow Chemical Co
•
Filing: 1950-09-14
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Granted: 1953-06-02
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Expires: 1970-09-14
Abstract
No abstract record available.
Inventors
- 👤 Paul H Cardwell
- 👤 Charles L Lunsford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:37
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/72; Y; Y10; Y10S; Y10S507/00; Y10S507/933; Y10S507/934
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
51 words
IN ACIDIZING WITH AQUEOUS HYDROCHLORIC ACID A CALCAREOUS FORMATION CONTAINING A SILICATE CAPABLE OF SWELLING AS THE ACID BECOMES SPENT ON ATTACKING THE CALCAREOUS MATTER, THE IMPROVED ACIDIZING METHOD WHICH CONSISTS IN INCLUDING IN THE ACID SOLUTION A BUFFERING AGENT SELECTED FROM THE GROUP CONSISTING OF FORMIC ACID AND ITS SALT.
Claim 2
Dependent Claim
51 words
IN ACIDIZING WITH AQUEOUS HYDROCHLORIC ACID A CALCAREOUS FORMATION CONTAINING A SILICATE CAPABLE OF SWELLING AS THE ACID BECOMES SPENT ON ATTACKING THE CALCAREOUS MATTER, THE IMPROVED ACIDIZING METHOD WHICH CONSISTS IN INCLUDING IN THE ACID SOLUTION A BUFFERING AGENT SELECTED FROM THE GROUP CONSISTING OF FORMIC ACID AND ITS SALT.
References Cited (Backward Citations)
US1877504A
Cited
US2024718A
Cited
US2045899A
Cited
US2234790A
Cited
US2301875A
Cited
US2238671A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |