Fabrication of pipe bundles offshore

Patent metadata

Field	Value
Publication number	US-11236550-B2
Application number	US-201816487081-A
Country	US
Kind code	B2
Filing date	Feb 20, 2018
Priority date	Feb 21, 2017
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A pipeline bundle for a riser tower or tie-back is manufactured offshore by suspending the bundle from an installation vessel, adding structural core sections successively to an upper end of the suspended bundle, lowering the bundle after adding each successive core section, and feeding one or more lengths of flowline pipe beside the core sections for incorporation into the bundle. The flowline pipe is coiled on a reel or carousel as a full-length piece before being uncoiled progressively as core sections are added to the lengthening bundle. The flowline pipe is then engaged with guide frames and/or buoyancy blocks supported by the core sections, by movement in a radially-inward direction through a radially-outer opening in a retainer formation. The opening is then closed to hold the flowline pipe in the retainer formation.

First claim

The invention claimed is:

1. A method of assembling an elongate pipeline bundle offshore aboard an installation vessel, the method comprising:
suspending the bundle from the vessel so that the bundle hangs in an upright orientation underwater beneath the vessel;
successively attaching pre-fabricated elongate structural core sections to a corresponding uppermost core section already incorporated into the bundle, in each instance to become a newly-uppermost core section of the bundle;
each pre-fabricated elongate structural core section comprising a core pipe a guide frame that extends radially outwardly from the core pipe, and a buoyancy block; and,
after attaching each core section, lowering the bundle in a downward launch direction to suspend the bundle from the newly-uppermost core section;
wherein the method further comprises incorporating a portion of flowline pipe into the bundle aboard the vessel, another portion of that pipe already incorporated into the bundle extending along the bundle beside the successive core sections, by feeding the flowline pipe on a feed path converging with the launch direction and engaging the flowline pipe with the guide frames and the buoyancy blocks of the core sections, that pipe being a flexible pipe, a composite pipe or a rigid pipe.

2. The method of claim 1 , comprising uncoiling the flowline pipe from coiled storage for incorporation into the bundle.

3. The method of claim 1 , comprising bending the flowline pipe along its length to follow the feed path.

4. The method of claim 1 , comprising effecting relative movement of the flowline pipe in a radially-inward direction with respect to a core section for incorporation into the bundle.

5. The method of claim 4 , wherein said relative movement of the flowline pipe takes place as the bundle is lowered in the launch direction.

6. The method of claim 5 , wherein said relative movement of the flowline pipe is at least partially effected by movement of a core section in the launch direction.

7. The method of claim 6 , wherein said movement of the core section takes place after incorporation of that core section into the bundle.

8. The method of claim 4 , comprising inserting the flowline pipe into a longitudinally-extending retainer formation of the guide frame through a radially-outer opening of the retainer formation.

9. The method of claim 8 , comprising inserting the flowline pipe into the retainer formation progressively in a longitudinal direction.

10. The method of claim 9 , comprising inserting the flowline pipe first into a lower part of the retainer formation and then into an upper part of the retainer formation.

11. The method of claim 8 , further comprising closing the radially-outer opening of the retainer formation to hold the flowline pipe in the retainer formation.

12. The method of claim 11 , wherein the step of closing comprises pressing the flowline pipe into the retainer formation by applying a closure that closes the radially-outer opening of the retainer formation.

13. The method of claim 1 , wherein the flowline pipe extends along successive core sections of the bundle as a continuous piece.

14. The method of claim 1 , comprising storing the flowline pipe offshore as a full-length piece before incorporation into the bundle.

15. The method of claim 1 , comprising suspending the bundle from successive ones of the guide frames after lowering the bundle in the launch direction.

16. The method of claim 1 , further comprising engaging the flowline pipe with buoyancy blocks supported by core sections of the bundle.

17. The method of claim 1 , wherein the bundle is incorporated into a riser tower or a subsea tie-back.

18. An apparatus for assembling an elongate pipeline bundle offshore comprises:
hang-off equipment for suspending the bundle from the vessel;
a connection workstation for adding prefabricated structural core sections successively to an upper end of the suspended bundle, each pre-fabricated elongate structural core section comprising a core pipe, a guide frame that extends radially outwardly from the core pipe, and a buoyancy block;
lowering equipment for lowering the bundle in a downward launch direction after adding each successive core section; and
pipe feed equipment for feeding a length of flowline pipe beside the core sections for incorporation into the bundle by engaging with the guide frames and buoyancy blocks, the pipe feed equipment defining a feed path that converges downwardly with, but remains offset from, the launch direction.

19. The apparatus of claim 18 , further comprising lifting equipment for lifting the structural core sections to the upper end of the suspended bundle.

20. The apparatus of claim 18 , further comprising pipe storage upstream of the pipe feed equipment.

21. The apparatus of claim 20 , wherein the pipe storage is arranged to store the flowline pipe in a coiled configuration.

22. The apparatus of claim 18 , further comprising guide equipment for bending the flowline pipe along its length to follow the feed path.

23. The apparatus of claim 18 , wherein the feed path is arranged to divert the flowline pipe in a radially-inward direction with respect to a core section incorporated into the bundle.

24. The apparatus of claim 18 , wherein the feed path is disposed above the hang-off equipment.

25. An installation vessel comprising the apparatus of claim 18 .

Assignees

• Acergy France SAS

Inventors

• Menet Florent

Classifications

• E21B19/004

  supporting a riser from a drilling or production platform · CPC title

• F16L1/19 Primary

  the pipes being J-shaped · CPC title

• F16L1/205

  Pipe-laying ships (F16L1/225, F16L1/23 and F16L1/235 take precedence) · CPC title

• F16L1/202

  fixed on or to vessels · CPC title

• F16L1/15

  vertically · CPC title