Unbonded flexible armored riser pipe

Patent metadata

Field	Value
Publication number	US-9580972-B2
Application number	US-201414764675-A
Country	US
Kind code	B2
Filing date	Jan 30, 2014
Priority date	Feb 1, 2013
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

An unbonded flexible armored pipe for transportation of fluids. The pipe has a center axis and a length and includes a carcass and an innermost sealing sheath with an inner surface surrounding the carcass. The carcass includes at least one elongate armor element wound to surround the center axis with a winding angle to the center axis defining a winding direction and a supporting surface facing towards the inner surface of the innermost sealing sheath and with a supporting surface radius Sr. The supporting surface includes a primary surface area and a plurality of restraining regions in the form of orifices in and/or protuberances and/or indentations from the primary surface area, wherein the restraining regions each have a length determined along the winding direction of the elongate armor element which is up to about Sr times Π.

First claim

What is claimed is:

1. An unbonded flexible armored pipe for transportation of fluids, having a center axis and a length, said unbonded flexible armored pipe comprising:
a carcass; and
an innermost sealing sheath with an inner surface surrounding said carcass, wherein:
the carcass comprises:
at least one elongate armor element wound to surround the center axis with a winding angle to the center axis defining a winding direction, and
a supporting surface formed by the at least one elongate armor element, said supporting surface facing towards the inner surface of the innermost sealing sheath and having a supporting surface radius Sr, wherein the supporting surface of said carcass comprises a primary surface area and a plurality of restraining regions formed in said primary surface area, wherein the restraining regions each have a length determined along the winding direction of the elongate armor element which is less than a length of the elongate armor element.

2. The unbonded flexible armored pipe of claim 1 , wherein the restraining regions each have a length determined along the winding direction of the elongate armor element which is up to about ½ Sr.

3. The unbonded flexible armored pipe as claimed in claim 1 , wherein the primary surface area of the supporting surface has a curvature corresponding to a curvature of the inner surface of the innermost sealing sheath faced by the primary surface area.

4. The unbonded flexible armored pipe as claimed in claim 1 , wherein the carcass has a total primary surface area, and the inner surface of the innermost sealing sheath has an inner surface area, the total primary surface area is at least about 80% relative to the inner surface area.

5. The unbonded flexible armored pipe as claimed in claim 1 , wherein the carcass comprises a plurality of elongate element windings along the length of the pipe provided by the at least one elongate armor element wherein the carcass comprises an average gap between the supporting surface of adjacent elongate element windings which is about 3 mm or less.

6. The unbonded flexible armored pipe as claimed in claim 1 , wherein each of the plurality of restraining regions is surrounded by the primary surface area, said each of the plurality of restraining regions comprising at least one of protuberances or indentations from said primary surface area.

7. The unbonded flexible armored pipe as claimed in claim 1 , wherein the restraining regions each have a length determined along the winding direction of the elongate armor element which is at least about 0.1 Sr.

8. The unbonded flexible armored pipe as claimed in claim 1 , wherein the supporting surface has a width determined perpendicular to the elongate armor element and the restraining regions each have a width perpendicular to its length, wherein the width of the restraining regions is up to about 0.95 times the width of the supporting surface.

9. The unbonded flexible armored pipe as claimed in claim 1 , wherein the restraining regions each have a width from about 2 mm to about 10 cm perpendicular to its length.

10. The unbonded flexible armored pipe as claimed in claim 1 , wherein the at least one elongate armor element has a front side facing towards the axis of the pipe and a rear side facing away from the axis of the pipe, wherein the rear side of the at least one elongate armor element, when the elongate armor element is unwound to be in straight position, is substantially flat when disregarding the restraining regions.

11. The unbonded flexible armored pipe as claimed in claim 1 , wherein the restraining regions comprise a plurality of protuberances and wherein the respective protuberances have a protruding height determined as the maximal height from the primary surface area, which protruding height is at least about 0.5 mm.

12. The unbonded flexible armored pipe as claimed in claim 11 , wherein the protruding height of the respective protuberances is from about 3 mm to about 1 cm.

13. The unbonded flexible armored pipe as claimed in claim 11 , wherein the protuberances have a rounded shape and the protuberances have a round or oval base and taper upwards to their protruding height.

14. The unbonded flexible armored pipe as claimed in claim 13 , wherein the protuberances comprise a shape selected from lens-shaped, hemispherical, or half-sickle shaped.

15. The unbonded flexible armored pipe as claimed in claim 1 , wherein the restraining regions comprise a plurality of indentations, wherein the respective indentations have a depression depth determined as the maximal depth from the primary surface area, which depression depth is at least about 0.5 mm.

16. The unbonded flexible armored pipe as claimed in claim 1 , wherein the restraining regions have a round or oval periphery surrounded by primary surface area.

17. The unbonded flexible armored pipe as claimed in claim 1 , wherein the restraining regions are arranged along the length of the at least one elongate and wound armor element with a distance of from about 5 cm to about 25 cm.

18. The unbonded flexible armored pipe as claimed in claim 1 , wherein the restraining regions are arranged along the length of the at least one elongate and wound armor such that restraining region(s) in one winding is offset with respect to restraining region(s) in an adjacent winding.

19. The unbonded flexible armored pipe as claimed in claim 1 , wherein the carcass is made from metal and comprising helically wound, folded and interlocked strips of steel and/or helically wound, profiled steel wires.

20. The unbonded flexible armored pipe as claimed in claim 1 , wherein the innermost sealing sheath is in the form of an extruded layer comprising a fluoride containing polymer.

21. The unbonded flexible armored pipe of claim 1 , wherein the restraining regions are in the form of orifices in said primary surface area.

22. The unbonded flexible armored pipe of claim 1 , wherein the restraining regions are in the form of protuberances from said primary surface area.

23. The unbonded flexible armored pipe of claim 1 , wherein the restraining regions are in the form of indentations on said primary surface area.

Assignees

• Nat Oilwell Varco Denmark Is

Inventors

• Cappeln Christian Ditlev
• Skaaning Christian Emil

Classifications

• B32B1/08

  Tubular products · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• F16L11/082 Primary

  two layers · CPC title

• B29C47/0023

  Operations & Transport · mapped topic

• E21B17/01 Primary

  Risers · CPC title