US3603391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tubing anchor
Assignee: Individual
•
Filing: 1970-04-03
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Granted: 1971-09-07
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Expires: 1990-04-03
Abstract
Abstract A tubing anchor for anchoring the lower extremity of a string of oil well tubing to a well casing. The anchor includes a hollow cage formed with a longitudinal passage having transversely opening windows formed therein. Sliders are disposed in the windows are slidable from a retracted position in said windows to an extended position projecting from said windows for engagement with the surrounding casing. A flexible boot lines the interior wall of the passage and is adhered to the interior wall of the passage and also to the back surfaces of the sliders. The boot has sufficient stiffness to normally maintain the sliders retracted within the windows and has sufficient flexibility to enable the pressure buildup within such boot as a consequence of a predetermined head of liquid in the tubing to flex such boot outwardly in the area of such windows to move the sliders to their extended position for engagement with the casing surrounding the tubing to maintain the tubing anchored firmly with respect thereto.
Inventors
- 👤 Jack Yann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:14
CPC Classifications
E; E21; E21B; E21B23/00; E21B23/04; E21B23/0411; E21B23/04115; E21B23/0419
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
253 words
A tubing anchor for anchoring the lower extremity of a string of well tubing to the well casing, said anchor comprising: a hollow cage for receipt in said casing and formed with a longitudinal passage having a plurality of transversely opening, through windows formed in the wall thereof; sliders formed to closely fit said windows and slidably received in the respective windows for movement from a retracted position disengaged from the wall of said casing to an extended position projecting from said windows and frictionally engaged with said casing wall; a flexible boot lining the wall of said passage; and bonding means bonding said boot to the wall of said cage and to said sliders, said boot being characterized in that it has sufficient stiffness to normally maintain an unflexed configuration behind said sliders to maintain said sliders in said retracted position disengaged from said wall of said casing and having sufficient flexibility to enable a predetermined pressure within said passage to flex said boot outwardly behind sliders to shift said sliders to their extended position whereby said boot will maintain said sliders retracted while said anchor is inserted in said casing and when fluid pressure builds up in said passage said boot will seal the fluid from passage through said windows and when the pressure in said boot reaches said predetermined pressure said boot will flex outwardly behind said sliders to move said sliders to said extended position for frictional engagement with said casing to anchor said tubing securely to said casing.
Claim 2
Dependent Claim
253 words
A tubing anchor for anchoring the lower extremity of a string of well tubing to the well casing, said anchor comprising: a hollow cage for receipt in said casing and formed with a longitudinal passage having a plurality of transversely opening, through windows formed in the wall thereof; sliders formed to closely fit said windows and slidably received in the respective windows for movement from a retracted position disengaged from the wall of said casing to an extended position projecting from said windows and frictionally engaged with said casing wall; a flexible boot lining the wall of said passage; and bonding means bonding said boot to the wall of said cage and to said sliders, said boot being characterized in that it has sufficient stiffness to normally maintain an unflexed configuration behind said sliders to maintain said sliders in said retracted position disengaged from said wall of said casing and having sufficient flexibility to enable a predetermined pressure within said passage to flex said boot outwardly behind sliders to shift said sliders to their extended position whereby said boot will maintain said sliders retracted while said anchor is inserted in said casing and when fluid pressure builds up in said passage said boot will seal the fluid from passage through said windows and when the pressure in said boot reaches said predetermined pressure said boot will flex outwardly behind said sliders to move said sliders to said extended position for frictional engagement with said casing to anchor said tubing securely to said casing.
Claim 3
Dependent Claim
41 words
A tubing anchor as set forth in claim 1 wherein: said windows are arranged in at least two rows spaced vertically from one another whereby each individual window may be relatively small while the cumulative area thereof will be relatively large.
Claim 4
Dependent Claim
24 words
A tubing Anchor as set forth in claim 1 wherein: said sliders are formed with relatively smooth exterior surfaces for engagement with said casing.
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) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |