Patent US3786878A successfully refreshed from Google Patents.
US3786878A
Expired / Lapsed
US
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Dual concentric drillpipe
Assignee: Individual
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Filing: 1971-12-14
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Granted: 1974-01-22
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Expires: 1991-12-14
Abstract
Abstract A dual concentric drillstring assembly for use with rotary drilling apparatus and a downhole percussion motor in which the inner and outer pipes of each stand of drillpipe are rigidly secured together by full-length welded webs for minimized reduction in the annulus and maximized heat transfer between the inner and outer members of each stand of dual-wall pipe. Each stand of dual-wall pipe is equipped with web-welded dual box-andpin tool joints so that coupling rotation of one stand of the drillpipe will simultaneously form two fluid-tight thread-coupled joints; the outer joint is fully thread-coupled while the inner joint is thread-coupled and includes a resilient seal at the interface between adjacent pipe joints so that full make-up of the inner pipe joint is not essential for sealing. For replacement of a worn pipe joint, cutting of the single outer pipe weld permits uncoupling of the dual pipe joint from the inner and outer pipe members of a stand.
Inventors
- 👤 H Sherman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:27
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/12; E21B17/00; E21B17/18; F; F16; F16L; F16L39/00; F16L39/005; F16L9/00; F16L9/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
284 words
A dual-wall drilling string comprising, in combination: i. a series of stands of dual-wall metallic pipe interconnectible in en-to-end relationship to form a drilling string, said stands each including an outer pipe member and an inner pipe member rigidly secured to and in coaxial spaced relationship with said outer pipe member and defining an internal longitudinal bore and an annular longitudinal passage surrounding said longitudinal bore and isolated therefrom; ii. box joints on a first end of each of said interconnected inner and outer pipe members of each such stand; iii. pin joints on a second end of each of said interconnected inner and outer pipe members of each such stand; iv. threaded portions on the distal ends of each of said box joints and said pin joints having similar threads of equal thread pitch and adapted to permit simultaneous make-up of said outer and inner pipe members of a pair of stands of said dualwall metallic pipe in end-to-end relationship, the threaded portion on said outer pipe box member of a first stand cooperating with the threaded portion on the outer pipe pin member of an interconnectible second stand to engage in fully made-up condition before the fully madeup coNdition of the inner pipe box member of said first stand with the inner pipe pin member of said second stand; and v. resilient sealing means between said inner pipe box member of said first stand and said inner pipe pin member of said interconnectible second stand; and successive stands of said drillpipe being thereby adapted to couple in end-to-end relationship to form a continuous drillstring having a continuous longitudinal bore and a continuous longitudinal annular passage surrounding said longitudinal bore and isolated therefrom.
Claim 2
Dependent Claim
284 words
A dual-wall drilling string comprising, in combination: i. a series of stands of dual-wall metallic pipe interconnectible in en-to-end relationship to form a drilling string, said stands each including an outer pipe member and an inner pipe member rigidly secured to and in coaxial spaced relationship with said outer pipe member and defining an internal longitudinal bore and an annular longitudinal passage surrounding said longitudinal bore and isolated therefrom; ii. box joints on a first end of each of said interconnected inner and outer pipe members of each such stand; iii. pin joints on a second end of each of said interconnected inner and outer pipe members of each such stand; iv. threaded portions on the distal ends of each of said box joints and said pin joints having similar threads of equal thread pitch and adapted to permit simultaneous make-up of said outer and inner pipe members of a pair of stands of said dualwall metallic pipe in end-to-end relationship, the threaded portion on said outer pipe box member of a first stand cooperating with the threaded portion on the outer pipe pin member of an interconnectible second stand to engage in fully made-up condition before the fully madeup coNdition of the inner pipe box member of said first stand with the inner pipe pin member of said second stand; and v. resilient sealing means between said inner pipe box member of said first stand and said inner pipe pin member of said interconnectible second stand; and successive stands of said drillpipe being thereby adapted to couple in end-to-end relationship to form a continuous drillstring having a continuous longitudinal bore and a continuous longitudinal annular passage surrounding said longitudinal bore and isolated therefrom.
Claim 3
Dependent Claim
54 words
Dual-wall drilling string as defined in claim 1, additionally including in each of said stands of dual-wall metallic pipe a plurality of metallic radial webs rigidly interconnecting said inner and outer concentric pipes of each of said stands and extending longitudinally within each of said annular longitudinal passages for substantially in full length thereof.
Claim 4
Dependent Claim
226 words
Dual-wall drilling string as disclosed in claim 1 in which: i. the box joint on the first end of said outer pipe member comprises a tubular outer pipe box joint member having internal threads thereon; ii. the box joint on the first end of said inner pipe member comprising a tubular inner pipe box joint member adjacent said outer pipe box joint member, having internal threads thereon of a thread pitch equal to the pitch of said internal threads on said outer pipe box joint member, said outer pipe box joint member and said inner pipe box joint member defining an annular box joint fluid passage therebetween communicating with said annular longitudinal passage; iii. the pin joint on the second end of said outer pipe member comprising a tubular outer pipe pin joint member having external threads thereon adapted to register with the internal threads of said outer pipe box joint member; iv. the pin joint on the second end of said inner pipe member comprising a tubular inner pipe pin joint member adjacent said outer pipe pin joint member and having external threads thereon adapted to register with the internal threads of said inner pipe box joint member, said outer pipe pin joint member and said inner pipe pin joint member defining an annular pin joint fluid passage therebetween communicating with said annular longitudinal passage.
Claim 5
Dependent Claim
75 words
Dual-wall concentric drillpipe as disclosed in claim 3 in which: i. said outer pipe box joint member and said inner pipe box joint member are rigidly secured together by a plurality of metal lugs radially spanning said annular box joint fluid passage; and ii. said outer pipe pin joint member and said inner pipe pin joint member are rigidly secured together by a plurality of metal lugs radially spanning said annular pin joint fluid passage.
Claim 6
Dependent Claim
67 words
Dual-wall concentric drillpipe as disclosed in claim 1 additionally including an inner pipe pin joint O-ring seal assembly on the outer surface of said inner pipe pin joint member; and a cylindrical O-ring seal face on the inner surface of said inner pipe box joint member adapted to register with the inner pipe pin joint O-ring seal assembly of a connecting similar stand of dual-wall concentric drillpipe.
Claim 7
Dependent Claim
55 words
Dual-wall concentric drillpipe as disclosed in claim 1 in which said outer pipe box joint member and said outer pipe pin joint member are each welded to said outer pipe; and additionally comprising thread means securing each of said inner pipe box joint members and said inner pipe pin joint members to said inner pipe.
Claim 8
Dependent Claim
83 words
Dual-wall concentric drillpipe as dislcosed in claim 1 in which said outer pipe box joint member and said outer pipe pin joint member are each welded to said outer pipe; and additionally comprising thread means securing each of said inner pipe box joint member and said inner pipe pin joint member to said inner pipe; and additionally comprising resilient sealing means on the interfaces between said inner pipe box joint member and said inner pipe pin joint member, respectively, and said inner pipe.
Claim 9
Dependent Claim
196 words
Dual-wall concentric drillpipe as disclosed in Claim 1 in which said inner pipe box joint member of each stand of said drillpipe is disposed in coaxial spaced relationship with said outer pipe box joint member thereof so that the distal end of said inner pipe box joint member is displaced substantially longitudinally inwardly from the distal end of said outer pipe box joint member thereof; and in which said inner pipe pin joint member of each stand of drillpipe is disposed in coaxial spaced relationship within said outer pipe pin joint member thereof so that the distal end of said inner pipe pin joint member is substantially coplanar with the distal end of said outer pipe pin joint member thereof, thereby effecting engagement of the internal threads of said outer pipe box joint member of a first stand of drillpipe with the external threads of the outer pipe pin joint member of a similar second stand of drillpipe connecting therewith before engagement of the internal threads of said inner pipe box joint member of said first stand of drillpipe with the external threads of the inner pipe pin joint member of said second stand of drillpipe.
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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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |