US4728224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aramid composite well riser for deep water offshore structures
Assignee: ConocoPhillips Co
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Filing: 1986-04-28
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Granted: 1988-03-01
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Expires: 2006-04-28
Abstract
Abstract Lightweight well riser elements for offshore platforms are formed of an aramid fiber/resin matrix material. The well risers are preferably in tubular form and include metallic end connectors for interconnecting a plurality of tubular members to form a well riser. Alternatively, the well riser may be formed in one piece extending for the entire length from a subsea template to the well deck on a floating platform.
Inventors
- 👤 Mamdouh M. Salama
- 👤 John A. Mercier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:42
CPC Classifications
F; F16; F16L; F16L11/00; F16L11/04; F16L11/08; F16L11/081; F16L11/083; B; B63; B63B; B63B21/00; B63B21/50; B63B21/502; D; D07; D07B; D07B1/00; D07B1/12; E; E02; E02B; E02B17/00; E02B17/0017; E02B17/003; E21; E21B; E21B17/00; E21B17/01; E21B17/20; F16L11/02; F16L9/00; F16L9/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
118 words
In a floating tension leg platform wherein a plurality of substantially vertically oriented, tensioned well risers are connected so as to be constantly in tension between a subsea template located on a sea bottom and said floating platform, the improvement which comprises each of said well risers being a lightweight composite structure of a plurality of longitudinally and circumferentially oriented first aramid fibers embedded in a resin matrix, the aramid fibers having an elastic modulus of less than about twenty million psi, said composite structure having a resulting low axial stiffness permitting sufficient elongation of said riser to accommodate variations in distance between said subsea template and said floating platform without the use of a conventional riser tensioner.
Claim 2
Dependent Claim
118 words
In a floating tension leg platform wherein a plurality of substantially vertically oriented, tensioned well risers are connected so as to be constantly in tension between a subsea template located on a sea bottom and said floating platform, the improvement which comprises each of said well risers being a lightweight composite structure of a plurality of longitudinally and circumferentially oriented first aramid fibers embedded in a resin matrix, the aramid fibers having an elastic modulus of less than about twenty million psi, said composite structure having a resulting low axial stiffness permitting sufficient elongation of said riser to accommodate variations in distance between said subsea template and said floating platform without the use of a conventional riser tensioner.
Claim 3
Dependent Claim
23 words
The improvement as set forth in claim 1 wherein said well risers are in sections and have metallic connectors disposed between said sections.
Claim 4
Dependent Claim
16 words
The improvement as set forth in claim 2 wherein said well risers are tubular in cross-section.
Claim 5
Dependent Claim
16 words
The improvement as set forth in claim 2 wherein said metallic connectors are threaded for interconnection.
Claim 6
Dependent Claim
15 words
The improvement as set forth in claim 2 wherein said metallic connectors are welded together.
Claim 7
Dependent Claim
21 words
The improvement as set forth in claim 1 wherein said longitudinally oriented aramid fibers have a low pitch angle helical lay.
Claim 8
Dependent Claim
24 words
The improvement as set forth in claim 6 wherein said circumferentially oriented aramid fibers have a lower elastic modulus than said longitudinally oriented fibers.
Claim 9
Dependent Claim
17 words
The improvement as set forth in claim 7 wherein said circumferentially oriented aramid fibers are helically wound.
Claim 10
Dependent Claim
25 words
The improvement as set forth in claim 8 wherein the composite structure comprises a plurality of alternating layers of longitudinally and circumferentially oriented aramid fibers.
Claim 11
Dependent Claim
16 words
The improvement as set forth in claim 1 wherein said resin matrix is a thermoset resin.
Claim 12
Dependent Claim
16 words
The improvement as set forth in claim 1 wherein said resin matrix is a thermoplastic resin.
Claim 13
Dependent Claim
18 words
The improvement as set forth in claim 1 wherein said composite structure includes internal and external elastomeric liners.
Claim 14
Dependent Claim
17 words
The improvement as set forth in claim 12 wherein said external elastomeric liner includes an antiflouling material.
Claim 15
Dependent Claim
15 words
The improvement as set forth in claim 13 wherein said antifouling material is particulate copper.
References Cited (Backward Citations)
US4484840A
Cited
US4589801A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |