US3574357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal insulating tubing
Assignee: GRUPUL IND PENTRU FORAY SI EXT
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Filing: 1969-02-27
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Granted: 1971-04-13
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Expires: 1989-02-27
Abstract
Abstract An insulated pipe for a deep-well string comprises two coaxial tubes, one inside the other, with a mass of thermal insulation between them. The inner tube has an enlarged upper end and a lower end that extends beyond the outer tube to allow two such pipes to telescope together. A ring connects the enlarged end of the inner tube to the inside of the outer tube while a second ring connected only to the inside of the outer tube serves as a guide for the inner tube, thereby allowing longitudinal expansion thereof. The rings act as axial walls confining the insulating mass between them.
Inventors
- 👤 Cassius Alexandru
- 👤 Petre Mihailescu
- 👤 Alexandru Stanescu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:20
CPC Classifications
E; E21; E21B; E21B36/00; E21B36/003; E21B17/00; E21B17/02; E21B17/04; F; F16; F16L; F16L59/00; F16L59/14; F16L59/143; F16L59/16; F16L59/18; F16L59/181
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
159 words
An insulated pipe for a well string, said pipe comprising: an inner tube; an outer tube coaxially spacedly surrounding said inner tube and forming an elongated annular chamber therewith; a first ring in one end of said chamber having an inner periphery connected to the exterior of said inner tube and an outer periphery connected to the interior of said outer tube; a second ring in the other end of said chamber having an outer periphery connected to the interior of said outer tube and receiving said inner tube with clearance; and thermal insulation filling said chamber between said rings, one of said rings being substantially flush with one end of said outer tube, and the other of said rings being inset from the other end of said outer tube, and an insulating bushing between said other end of said outer tube and said other of said rings, said bushing having a radial extent limited by said outer tube.
Claim 2
Dependent Claim
159 words
An insulated pipe for a well string, said pipe comprising: an inner tube; an outer tube coaxially spacedly surrounding said inner tube and forming an elongated annular chamber therewith; a first ring in one end of said chamber having an inner periphery connected to the exterior of said inner tube and an outer periphery connected to the interior of said outer tube; a second ring in the other end of said chamber having an outer periphery connected to the interior of said outer tube and receiving said inner tube with clearance; and thermal insulation filling said chamber between said rings, one of said rings being substantially flush with one end of said outer tube, and the other of said rings being inset from the other end of said outer tube, and an insulating bushing between said other end of said outer tube and said other of said rings, said bushing having a radial extent limited by said outer tube.
Claim 3
Dependent Claim
28 words
The pipe defined in claim 1, further comprising a ring threadedly engageable with the interior of said other of said ends for holding said insulating bushing in place.
Claim 4
Dependent Claim
46 words
The pipe defined in claim 1 wherein said rings are connected but circumferential welding to said tubes and one end of said inner tube projects beyond one end of said outer tube and is adapted to engage telescopically the other end of another such inner tube.
Claim 5
Dependent Claim
27 words
The pipe defined in claim 3 wherein said one end of said inner tube is telescopically received in said other end of said other such inner tube.
Claim 6
Dependent Claim
16 words
The pipe defined in claim 1 wherein said one of said rings is said first ring.
Claim 7
Dependent Claim
17 words
The pipe defined in claim 1, further comprising connecting means for longitudinally coupling two such pipes together.
Claim 8
Dependent Claim
38 words
The pipe defined in claim 6 wherein said connecting means comprises an internally threaded sleeve threadedly engageable with ends of two such outer tubes, and an insulating washer engageable between said ends of said two such outer tubes.
Claim 9
Dependent Claim
220 words
A sellstring assembly comprising two pipes each including: an inner tube; an outer tube coaxially spacedly surrounding said inner tube and forming an elongated annular chamber therewith; a first ring in one end of said chamber having an inner periphery connected to the exterior of said inner tube and an outer periphery connected to the interior of said outer tube; a second ring in the other end of said chamber having an outer periphery connected to the interior of said outer tube and receiving said inner tube with clearance; thermal insulation filling said chamber between said rings; and connecting means for longitudinally coupling said two pipes together, each of said inner tubes having one end substantially flush with one end of the respective outer tube and another end projecting beyond the other end of said respective outer tube, said one end of one of said inner tubes being telescopically engaged with the other end of the other of said inner tubes, said connecting means comprising a sleeve and a washer, said sleeve threadedly engaging said one end of said one of said outer tubes, said washer being engaged between said one end of said one of said outer tubes and said other end of said other of said outer tubes, said washer having a radial extent defined by said sleeve.
Claim 10
Dependent Claim
220 words
A sellstring assembly comprising two pipes each including: an inner tube; an outer tube coaxially spacedly surrounding said inner tube and forming an elongated annular chamber therewith; a first ring in one end of said chamber having an inner periphery connected to the exterior of said inner tube and an outer periphery connected to the interior of said outer tube; a second ring in the other end of said chamber having an outer periphery connected to the interior of said outer tube and receiving said inner tube with clearance; thermal insulation filling said chamber between said rings; and connecting means for longitudinally coupling said two pipes together, each of said inner tubes having one end substantially flush with one end of the respective outer tube and another end projecting beyond the other end of said respective outer tube, said one end of one of said inner tubes being telescopically engaged with the other end of the other of said inner tubes, said connecting means comprising a sleeve and a washer, said sleeve threadedly engaging said one end of said one of said outer tubes, said washer being engaged between said one end of said one of said outer tubes and said other end of said other of said outer tubes, said washer having a radial extent defined by said sleeve.
Claim 11
Dependent Claim
17 words
The pipe defined in claim 8 wherein said rings are connected by circumferential welding to said tubes.
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) | 1974-04-12 | 1974-10-12 | 1975-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-12 | 1978-10-12 | 1979-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-12 | 1982-10-12 | 1983-04-13 | $7700.00 | Window Closed / Lapsed |