# US 2018/0023767 A1 · Sealing Arrangements for Subsea Pipe-in-Pipe Systems

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- Number: US 2018/0023767 A1
- Document ID: US20180023767A1
- Status: Published application
- Kind: A1
- Application number: 15/547,791
- Filed: 2016-02-02
- Published: 2018-01-25
- Earliest claimed: 2015-02-03
- Assignees: Acergy France SAS
- Applicants: Acergy France SAS
- Inventors: Nathalie Delaunay; Gerald Gerometta; Henri Rousseau
- Web page: https://patentgrep.com/patent/US20180023767A1

## CPC

- E21B 17/003: {with electrically conducting or insulating means (E21B17/028 and E21B17/023 take precedence)}
- E21B 36/003: {Insulating arrangements}
- E21B 36/005: {Heater surrounding production tube}
- E21B 36/04: using electrical heaters
- E21B 43/01: specially adapted for obtaining from underwater installations
- E21B 43/013: Connecting a production flow line to an underwater well head
- F16L 1/123: {Devices for the protection of pipes under water}
- F16L 1/16: on the bottom
- F16L 7/00: Supporting pipes or cables inside other pipes or sleeves, e.g. for enabling pipes or cables to be inserted or withdrawn from under roads or railways without interruption of traffic (sleeves for supporting pipes, cables or protective tubing, between relatively movable points F16L3/01)
- F16L 7/02: and sealing the pipes or cables inside the other pipes, cables or sleeves
- F16L 9/18: Double-walled pipes; Multi-channel pipes or pipe assemblies
- F16L 9/20: {Pipe assemblies}
- F16L 53/30: Heating of pipes or pipe systems
- F16L 53/38: using elongate electric heating elements, e.g. wires or ribbons
- F16L 59/065: using vacuum (F16L59/075 takes precedence)
- F17D 1/18: by heating
- F17D 3/01: for controlling, signalling, or supervising the conveyance of a product
- H05B 3/42: non-flexible
- F16L 9/19: Multi-channel pipes or pipe assemblies
- H05B 2214/03: Heating of hydrocarbons
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F17D: PIPE-LINE SYSTEMS; PIPE-LINES (pumps or compressors F04; fluid dynamics F15D; valves or the like F16K; pipes, laying pipes, supports, joints, branches, repairing, work on the entire line, accessories F16L; steam traps or the like F16T; fluid-pressure electric cables H01B9/06)
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL

## Abstract

A method of sealing an annulus of an electrically trace-heated pipe-in-pipe structure including introducing a flowable filler material to mould 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.

## Claims

### Claim 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 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.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 1)

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.

### Claim 4 (depends on 3)

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

### Claim 5 (depends on 1)

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.

### Claim 6 (depends on 1)

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.

### Claim 7 (depends on 6)

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.

### Claim 8 (depends on 1)

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

### Claim 9 (depends on 7)

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

### Claim 10 (depends on 1)

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.

### Claim 11 (depends on 1)

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.

### Claim 12 (depends on 11)

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.

### Claim 13 (depends on 11)

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.

### Claim 14 (depends on 13)

The structure of claim 13, wherein a plurality of heating elements extend individually through a corresponding plurality of bores, each bore containing a respective sealing mass that seals around a respective one of the heating elements and that closes the bore.

### Claim 15 (depends on 14)

The structure of claim 14, wherein two or more of the sealing masses are joined outside the bores.

### Claim 16 (depends on 13)

The structure of any of claim 13, wherein the projections are joined by an intermediate ring through which one or more bores extend longitudinally.

### Claim 17 (depends on 1)

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.

### Claim 18 (depends on 17)

The structure of claim 17, wherein the filling channel intersects radially with the restriction.

### Claim 19 (depends on 17)

The structure of claim 17, wherein the filling channel is positioned radially outboard of the restriction in the outer ring and/or in a projection that extends radially into the annulus from the outer ring, and communicates with a plurality of further channels that lead to the restriction.

### Claim 20 (depends on 17)

The structure of claim 17, wherein the filling channel is radially outboard of the outer ring and communicates with a plurality of ports in the outer ring that lead to the restriction.

### Claim 21 (depends on 1)

The structure of claim 1, wherein at least one projection is integral with either or both of said rings.

### Claim 22 (depends on 1)

The structure of claim 1, wherein at least one of the inner and outer rings is integral with an inner or outer pipe.

### Claim 23 (depends on 1)

The structure of claim 1, wherein at least one of the inner and outer rings is attached to an inner or outer pipe.

### Claim 24 (depends on 1)

The structure of claim 1, wherein the inner and outer rings are conjoined via the or each radially-extending projection.

### Claim 25

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 through the restriction.

### Claim 26 (depends on 25)

The method of claim 25, comprising placing the or each heating element into the restriction before moulding the filler material.

### Claim 27 (depends on 26)

The method of claim 26, comprising inserting the or each heating element into one or more bores of the restriction.

### Claim 28 (depends on 25)

The method of claim 25, comprising creating the restriction around the or each heating element before moulding the filler material.

### Claim 29 (depends on 28)

The method of claim 28, comprising supporting the or each heating element on the inner ring and then placing the outer ring around the or each heating element to complete the restriction.

### Claim 30 (depends on 29)

The method of claim 29, comprising laying the or each heating element across a projection of the inner ring that at least partially defines the restriction, the or each heating element following an external contour of that projection.

### Claim 31 (depends on 29)

The method of claim 29, comprising opposing the or each heating element with a projection of the outer ring that at least partially defines the restriction.

### Claim 32 (depends on 25)

The method of claim 25, comprising introducing the filler material into the restriction through the outer ring.

### Claim 33 (depends on 32)

The method of claim 32, comprising distributing the filler material circumferentially before the filler material enters the restriction.

### Claim 34 (depends on 25)

The method of claim 25, comprising introducing the filler material into the restriction along the annulus.

### Claim 35 (depends on 25)

The method of claim 25, comprising dividing the filler material between circumferentially-spaced bores of the restriction.

### Claim 36 (depends on 25)

The method of claim 25, comprising extending the sealing mass into at least one space of the restriction at which the annulus tapers longitudinally.