US3768565A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Friction reducing
Assignee: Calgon Corp
•
Filing: 1971-09-29
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Granted: 1973-10-30
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Expires: 1991-09-29
Abstract
Abstract Polymers containing 2-acrylamido-2-methylpropane sulfonic acid are useful as friction reducers for aqueous fluids flowing through a conduit, especially for the aqueous hydraulic fracturing of subterranean formations.
Inventors
- 👤 L Persinski
- 👤 J Boothe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:42
CPC Classifications
C; C09; C09K; C09K3/00; C09K8/00; C09K8/60; C09K8/62; Y; Y10; Y10S; Y10S507/00; Y10S507/922; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0391
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
79 words
An improved process for hydraulically fracturing an earth formation penetrated by a well comprising injecting an aqueous fracturing fluid down the well into the earth formation under pressure to cause fracturing of the earth formation wherein the improvement comprises treating the aqueous fracturing fluid prior to injection with an effective amount of a random, linear, water-soluble polymer consistiNg essentially of from about 2.5 to 100 mole percent 2-acrylamido-2-methylpropane sulfonic acid and from 0 to about 97.5 mole percent acrylamide.
Claim 2
Dependent Claim
28 words
A method of claim 2 wherein the amount of polymer employed is about 50 to 1,000 ppm by weight based on the weight of the aqueous fracturing fluid.
Claim 3
Dependent Claim
17 words
A method of claim 2 wherein the polymer has a molecular weight of at least about 1,000,000.
Claim 4
Dependent Claim
17 words
A method of claim 3 wherein the polymer has a molecular weight of at least about 1,000,000.
References Cited (Backward Citations)
CA864433A
Cited
US3023760A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |