Method for protecting field joint arrangement for a pipeline

Patent metadata

Field	Value
Publication number	US-10295111-B2
Application number	US-201515538186-A
Country	US
Kind code	B2
Filing date	Dec 22, 2015
Priority date	Dec 24, 2014
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A method protects a field joint of a pipeline, where chamfered edges of thermally-insulating parent coatings on conjoined pipe lengths are in mutual opposition about a longitudinally-extending gap. The method includes manufacturing an hourglass-shaped inner layer around the pipe lengths, which layer may be moulded. The inner layer extends longitudinally along the gap between the chamfered edges and at least partially overlies the chamfered edges. A thermally-insulating solid insert is assembled from two or more parts to lie in the gap surrounding the inner layer, and pressure is applied radially inwardly from the insert to the inner layer. An outer layer of molten material is manufactured around the insert to form a watertight barrier and to form one or more melted interfaces with the inner layer. Corresponding field joint arrangements are also disclosed.

First claim

The invention claimed is:

1. A method of protecting a field joint of a pipeline at which chamfered edges of thermally-insulating parent coatings on conjoined pipe lengths are in mutual opposition about a longitudinally-extending gap, the method comprising:
manufacturing an hourglass-shaped inner layer around the pipe lengths, which layer extends longitudinally along the gap between the chamfered edges and at least partially overlies the chamfered edges;
assembling a thermally-insulating solid insert from two or more parts to lie in the gap surrounding the inner layer;
applying radially-inward pressure from the insert to the inner layer; and
manufacturing an outer layer around the insert using molten material to form a watertight barrier and to form one or more melted interfaces with the inner layer.

2. The method of claim 1 , comprising elastically compressing the inner layer by said radially-inward pressure.

3. The method of claim 1 , comprising plastically deforming the inner layer by said radially-inward pressure.

4. The method of claim 1 , where the inner layer is a thermoplastic, comprising pressing the insert into the inner layer when the inner layer is at a softening temperature.

5. The method of claim 1 , comprising maintaining said radially-inward pressure on the inner layer during and after manufacturing the outer layer.

6. The method of claim 5 , comprising holding together the parts of the insert under tension in one or more fastenings that connect those parts.

7. The method of claim 6 , comprising press-fitting the parts of the insert together to engage the fastenings and to apply radially inward pressure to the inner layer.

8. The method of claim 1 , further comprising applying an anti-corrosion layer and an adhesive primer layer onto the pipe lengths before manufacturing the inner layer.

9. The method of claim 1 , wherein the inner layer is moulded around the joined pipe lengths.

10. The method of claim 1 , wherein the inner layer is wound or wrapped around the joined pipe lengths.

11. The method of claim 10 , wherein the inner layer is extruded in situ.

12. The method of claim 1 , wherein the outer layer is moulded around the insert.

13. The method of claim 1 , wherein the outer layer is wrapped around the insert.

14. The method of claim 13 , wherein the outer layer is extruded in situ.

Assignees

• Subsea 7 Ltd

Inventors

• Monfort-Moros Nicolas
• Popineau Sylvain
• Hoffmann Philippe Benoit Jacques

Classifications

• B29C45/14819

  the inserts being completely encapsulated · CPC title

• B29C65/542

  by injection · CPC title

• F16L59/20 Primary

  for non-disconnectable joints · CPC title

• F16L59/024

  consisting of two half sleeves · CPC title

• F16L1/00

  Laying or reclaiming pipes; Repairing or joining pipes on or under water · CPC title