Patent US984434A successfully refreshed from Google Patents.
Patent US3766980A successfully refreshed from Google Patents.
US3766980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permafrost and well protection
Assignee: Atlantic Richfield Co
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Filing: 1972-08-07
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Granted: 1973-10-23
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Expires: 1992-08-07
Abstract
Abstract A method for protecting a permafrost zone and a well passing through that permafrost zone wherein a pipe string is placed in said well so as to extend through at least part of said permafrost zone and is heated over its length in said permafrost zone using electrical energy thereby avoiding alternate freezing and thawing of the permafrost and sloughing of the permafrost due to thermal cycling and preventing freeze up of the well itself.
Inventors
- 👤 L Kern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:01
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/16; E21B43/24; E21B43/2401; E21B36/00; Y; Y10; Y10S; Y10S166/00; Y10S166/901
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
53 words
A method of proTecting a permafrost zone around a well and the well which passes through said permafrost zone comprising emplacing a pipe string in said well which extends through at least part of said permafrost zone, and heating said pipe string uniformly over its length in said permafrost zone using electrical energy.
Claim 2
Independent Claim
53 words
A method of proTecting a permafrost zone around a well and the well which passes through said permafrost zone comprising emplacing a pipe string in said well which extends through at least part of said permafrost zone, and heating said pipe string uniformly over its length in said permafrost zone using electrical energy.
Claim 3
Dependent Claim
35 words
A method according to claim 1 wherein said pipe string is heated by applying an electrical current directly to an upper portion of said pipe string, and returning said current from beneath said permafrost zone.
Claim 4
Dependent Claim
12 words
A method according to claim 2 wherein said current is alternating current.
Claim 5
Dependent Claim
12 words
A method according to claim 2 wherein said current is direct current.
Claim 6
Dependent Claim
24 words
A method according to claim 4 wherein said pipe string is protected from electrolytic corrosion by connecting to said pipe string a sacrifical anode.
Claim 7
Dependent Claim
55 words
A method according to claim 1 wherein said pipe string is heated by placing at least one electrical conductor in said well along at least part of the length of said permafrost zone and near said pipe string, and passing electrical current through said conductor to heat same and in turn heat said pipe string.
Claim 8
Dependent Claim
47 words
A method according to claim 1 wherein said pipe string is heated by employing at least one electric conductor physically attached to at least one wall of said pipe string, and passing electrical current through said conductor to heat same and in turn heat said pipe string.
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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |