US3664441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Concentric pipe drill string
Assignee: AMF GEO SPACE Corp A CORP OF TEXAS
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Filing: 1970-06-01
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Granted: 1972-05-23
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Expires: 1990-06-01
Abstract
Abstract This invention contemplates stands of concentric drill pipes with tool joints which are disconnectable from the pipes for use in oil well drilling. The removable tool joints provide means for supporting and maintaining the inner tube in coaxial relationship within the surrounding outer pipe within each stand.
Inventors
- 👤 Paul P Carey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:58
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/18; E21B17/02; E21B17/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
205 words
An apparatus including a plurality of concentric pipe stands removably connected above the drill bit in an oil or gas well drill string, each pipe stand comprising: an outer pipe, a tool joint pin threadedly secured to one end of said outer pipe, a tool joint box threadedly secured to the other end of said outer pipe, one of said tool joints defining a support surface, the other of said tool joints defining a stop surface; an inner tube concentrically arranged within said outer pipe, a first set of lugs radially extending from one end of said tube, a second set of lugs radially extending from the other end of said tube; said first set of lugs being supported by said support surface; said second set of lugs being limited by said stop surface when said inner tube elongates relative to said outer tube by an excessive amount; each tool joint comprising a cylindrical sleeve defining an inner cylindrical surface which is in frictional engagement with one set of lugs; each tube is provided with a cylindrical outer sleeve for telescopically receiving one end of an adjacent tube in said drill string, and a compressible annular seal ring between each pair of adjacent inner tubes.
Claim 2
Independent Claim
205 words
An apparatus including a plurality of concentric pipe stands removably connected above the drill bit in an oil or gas well drill string, each pipe stand comprising: an outer pipe, a tool joint pin threadedly secured to one end of said outer pipe, a tool joint box threadedly secured to the other end of said outer pipe, one of said tool joints defining a support surface, the other of said tool joints defining a stop surface; an inner tube concentrically arranged within said outer pipe, a first set of lugs radially extending from one end of said tube, a second set of lugs radially extending from the other end of said tube; said first set of lugs being supported by said support surface; said second set of lugs being limited by said stop surface when said inner tube elongates relative to said outer tube by an excessive amount; each tool joint comprising a cylindrical sleeve defining an inner cylindrical surface which is in frictional engagement with one set of lugs; each tube is provided with a cylindrical outer sleeve for telescopically receiving one end of an adjacent tube in said drill string, and a compressible annular seal ring between each pair of adjacent inner tubes.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |