Sealing arrangements for subsea pipe-in-pipe systems

Patent metadata

Field	Value
Publication number	US-10352107-B2
Application number	US-201615547791-A
Country	US
Kind code	B2
Filing date	Feb 2, 2016
Priority date	Feb 3, 2015
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A method of sealing an annulus of an electrically trace-heated pipe-in-pipe structure including introducing a flowable filler material to mold a sealing mass in situ is disclosed. The sealing mass closes a restriction at which the annulus is narrowed radially and embeds at least one heating element that extends generally longitudinally through the restriction. The structure includes an inner ring spaced within an outer ring to define the annulus between the rings. The annulus is narrowed radially by one or more projections that extend radially into the annulus from at least one of the rings toward the other of said rings. The restriction may include multiple bores, each of which may contain a sealing mass around a respective heating element in the bore.

First claim

The invention claimed is:

1. An electrically trace-heated pipe-in-pipe structure, comprising: an inner ring spaced within an outer ring to define an annulus between said rings; a restriction at which the annulus is narrowed radially by at least one projection that extends radially into the annulus from at least one of said rings toward the other of said rings; at least one elongate heating element extending generally longitudinally along the annulus and continuously through the restriction; and one or more in situ-moulded sealing masses that close the restriction radially and that embed the or each heating element in the restriction, such that the or each heating element extends continuously through the respective one or more sealing masses.

2. The structure of claim 1 , further comprising at least one insulating layer disposed in the annulus on a radially outer side of the or each heating element, which insulating layer is interrupted longitudinally at the restriction.

3. The structure of claim 1 , wherein at least one projection that defines the restriction comprises longitudinally-opposed inclined shoulders that define longitudinally-tapering spaces of the annulus.

4. The structure of claim 3 , wherein the or each sealing mass extends into the longitudinally-tapering spaces.

5. The structure of claim 1 , wherein the or each heating element extends longitudinally across at least one projection that defines the restriction, by following an external contour of that projection.

6. The structure of claim 1 , wherein the or each heating element extends along a female formation that is provided in at least one projection defining the restriction or that is provided between at least two of such projections.

7. The structure of claim 6 , wherein the female formation is a bore defined at least partially by a groove or a hole in or between the or each projection.

8. The structure of claim 7 , wherein the restriction further comprises at least one wall that bridges the restriction radially.

9. The structure of claim 1 , wherein the restriction comprises a plurality of circumferentially-spaced bores.

10. The structure of claim 1 , wherein the restriction is circumferentially continuous around the inner ring, being partially defined by a circumferentially-continuous land of the or each radially-extending projection.

11. The structure of claim 1 , wherein the restriction is defined between an inner projection that projects radially outwardly from the inner ring and an outer projection that projects radially inwardly from the outer ring.

12. The structure of claim 11 , wherein: the projections confront each other across the narrowed annulus; and the or each sealing mass seals against the projections and around the or each heating element extending through a gap between the projections, to close the gap.

13. The structure of claim 11 , wherein: the projections abut or join each other across the annulus; and a respective sealing mass seals around the or each heating element extending through one or more bores between the projections, to close the or each bore.

14. The structure of claim 1 , further comprising at least one circumferentially-extending filling channel that communicates between at least one port in the outer ring and the restriction.

15. A method of sealing an annulus of an electrically trace-heated pipe-in-pipe structure, which annulus is defined between an inner ring and an outer ring spaced outside the inner ring, the method comprising introducing a flowable filler material to mould in situ one or more sealing masses that close a restriction at which the annulus is narrowed radially and that embed at least one heating element that extends generally longitudinally and continuously through the restriction, such that the at least one heating element extends continuously through the one or more sealing masses.

16. The method of claim 15 , comprising placing the or each heating element into the restriction before moulding the filler material.

17. The method of claim 15 , comprising creating the restriction around the or each heating element before moulding the filler material.

18. The method of claim 15 , comprising introducing the filler material into the restriction through the outer ring.

19. The method of claim 18 , comprising distributing the filler material circumferentially before the filler material enters the restriction.

20. The method of claim 15 , comprising extending the sealing mass into at least one space of the restriction at which the annulus tapers longitudinally.

21. An electrically trace-heated pipe-in-pipe structure, comprising:
an inner ring spaced within an outer ring to define an annulus between said rings;
a restriction at which the annulus is narrowed radially by at least one projection that extends radially into the annulus from at least one of said rings toward the other of said rings; at least one elongate heating element extending generally longitudinally along the annulus and through the restriction;
one or more in situ-moulded sealing masses that close the restriction radially and that embed the or each heating element in the restriction; and
at least one circumferentially-extending filling channel that communicates between at least one port in the outer ring and the restriction to admit filler material to form the one or more sealing masses.

Assignees

• Acergy France SAS

Inventors

• Delaunay Nathalie
• Gerometta Gerald
• Rousseau Henri

Classifications

• F17D3/01

  for controlling, signalling, or supervising the conveyance of a product · CPC title

• F16L59/065

  using vacuum (F16L59/075 takes precedence) · CPC title

• H05B3/42

  non-flexible · CPC title

• F16L9/20

  Pipe assemblies · CPC title

• F16L1/16

  on the bottom · CPC title