In situ transfer and support of tensioned system and method for a flexible link

Patent metadata

Field	Value
Publication number	US-8997873-B2
Application number	US-201113323294-A
Country	US
Kind code	B2
Filing date	Dec 12, 2011
Priority date	Dec 12, 2011
Publication date	Apr 7, 2015
Grant date	Apr 7, 2015

Abstract

The disclosure provides an in-situ system and method for transferring a load from a tensioned flexible link between at least two bodies, such as between a buoyancy can and a subsea riser or between a moored offshore platform and a pile. The system and method provides a tether assembly having a hydraulic cylinder and/or a transfer assembly, where the hydraulic cylinder is configured upon actuation to decrease a distance between the two bodies; and the transfer assembly includes a mechanical interlock configured upon actuation to maintain the decreased distance between the two bodies independent of the hydraulic cylinder. The mechanical interlock can include various embodiments that can be selectively activated and deactivated position to allow the hydraulic cylinder to operate at various times in the transfer process. A support assembly can provide additional support to the flexible link independent of or in addition to the transfer assembly.

First claim

What is claimed is:

1. A system for in-situ transfer of at least a portion of a tensile load from a flexible link coupled between at least two bodies, comprising:
a first tether assembly coupled between the two bodies and comprising at least one hydraulic cylinder with a cylinder rod slidably disposed therein and at least one transfer assembly,
the hydraulic cylinder being configured upon actuation to decrease a distance between the two bodies and thereby transfer at least a portion of the tensile load from the flexible link to the tether assembly; and
the transfer assembly comprising:
a first transfer block;
a second transfer block;
the hydraulic cylinder coupled to the transfer blocks; and
a mechanical interlock configured upon mechanical actuation to maintain the decreased distance between the two bodies with at least a portion of the tensile load transferred to the tether assembly independently of the hydraulic cylinder.

2. The system of claim 1 , wherein the mechanical interlock comprises a first eccentric pulley rotatably coupled to one of the transfer blocks, the first eccentric pulley configured to allow a first distance between the two bodies in a first rotational position and a second distance between the two bodies that is shorter than the first distance in a second rotational position.

3. The system of claim 2 , further comprising a second pulley rotatably coupled to another of the transfer blocks different from the transfer block with the first eccentric pulley and a transfer sling coupled between the first eccentric pulley and the second pulley.

4. The system of claim 1 , wherein the mechanical interlock comprises:
a transfer leg coupled to one of the transfer blocks;
a receptacle coupled to another of the transfer blocks; and
a coupler coupled with the transfer leg, the receptacle, or both and configured to allow the transfer leg to be coupled to the receptacle at one or more positions to establish one or more lengths of the transfer assembly.

5. The system of claim 1 , wherein the mechanical interlock comprises:
a transfer leg coupled to one of the transfer blocks;
a receptacle coupled to another of the transfer blocks; and
a pin coupled with the transfer leg, the receptacle, or both and configured to allow the transfer leg to be coupled to the receptacle at one or more positions to establish one or more lengths of the transfer assembly.

6. The system of claim 1 , wherein the mechanical interlock comprises:
a transfer leg coupled to one of the transfer blocks;
a receptacle coupled to another of the transfer blocks; and
a clamshell coupled with the transfer leg, the receptacle, or both and configured to allow the transfer leg to be coupled to the receptacle at one or more positions to establish one or more lengths of the transfer assembly.

7. The system of claim 1 , wherein the mechanical interlock comprises:
a transfer leg coupled to one of the transfer blocks;
a receptacle coupled to another of the transfer blocks; and
a shim pin coupled with the transfer leg, the receptacle, or both and configured to allow the transfer leg to be coupled to the receptacle at one or more positions to establish one or more lengths of the transfer assembly, the pin having a first shim pin portion and a second shim pin portion with one or more shims inserted between the shim pin portions.

8. The system of claim 1 , wherein the mechanical interlock comprises:
a transfer leg coupled to one of the transfer blocks;
a receptacle coupled to another of the transfer blocks;
a clamshell coupled with the transfer leg, the receptacle, or both and configured to allow the transfer leg to be coupled to the receptacle at one or more positions to establish one or more lengths of the transfer assembly; and
one or more shims coupled between the clamshell and the receptacle.

9. The system of claim 1 , wherein the mechanical interlock comprises:
a transfer leg coupled to one of the transfer blocks;
a receptacle coupled to another of the transfer blocks;
a pin coupled with the transfer leg, the receptacle, or both and configured to allow the transfer leg to be coupled to the receptacle at one or more positions to establish one or more lengths of the transfer assembly; and
one or more shims coupled between the pin and the receptacle.

10. The system of claim 1 , further comprising a support assembly coupled between the two bodies in addition to the flexible link.

11. The system of claim 10 , wherein the support assembly comprises:
an upper support block coupled to an upper portion of the flexible link;
a lower support block coupled to a lower portion of the flexible link distal from the upper load support; and
at least one support link coupled between the upper support block and lower support block.

12. The system of claim 1 , wherein the two bodies comprise a buoyancy can and a riser support connection.

13. The system of claim 1 , wherein the two bodies comprise an offshore platform and a pile.

14. A method of in-situ transferring at least a portion of a tensile load from a flexible link coupled between two bodies, comprising:
coupling at least one tether assembly between the two bodies with a first distance established between the two bodies, the tether assembly having a transfer assembly with at least two transfer blocks and a hydraulic cylinder with an associated cylinder rod coupled to the transfer blocks;
activating the hydraulic cylinder to move the two bodies closer from the first distance to a second distance that is less than the first distance; and
mechanically interlocking by mechanically actuating the transfer assembly at the second distance independent of tension applied by the hydraulic cylinder to the transfer assembly.

15. The method of claim 14 , further comprising:
releasing the mechanical interlock on the transfer assembly; and
allowing the two bodies to separate to a distance greater than the second distance.

16. The method of claim 14 , further comprising:
transferring the tensile load from the flexible link to the at least one tether assembly; and
at least temporarily removing the flexible link from between the two bodies.

17. The method of claim 14 , further comprising:
transferring less than the tensile load from the flexible link to the at least one tether assembly; and
at least temporarily supporting the tensile load with the flexible link and the at least one tether assembly.

18. The method of claim 14 , wherein the transfer assembly comprises at least one eccentric pulley rotatably coupled to at least one of the transfer blocks and coupled to a transfer sling disposed between the transfer blocks, and wherein mechanically interlocking the transfer assembly at the second distance comprises rotating the eccentric pulley from a first rotational position to a second rotational position.

19. The method of claim 14 , wherein the transfer assembly comprises a transfer leg coupled to one of the transfer blocks and a receptacle coupled to another of the transfer blocks, and wherein mechanically interlocking the transfer assembly at the second distance comprises coupling a coupler to the transfer leg, the receptacle, or both at one or more positions to establish one or more lengths of the transfer assembly.

20. The method of claim 14 , wherein the transfer assembly comprises a transfer leg coupled to one of the transfer blocks and a receptacle coupled to another of the transfer blocks, and wherein mechanically interlocking the transfer assembly at the second dist

Assignees

• Riordan Brian
• Boisne Mathieu
• Selcer Tobias G
• Robbins Jacy Lee
• Luppi Ange
• Technip France

Inventors

• Riordan Brian
• Boisne Mathieu
• Selcer Tobias G
• Robbins Jacy Lee
• Luppi Ange

Classifications

• E21B17/015 Primary

  Non-vertical risers, e.g. articulated or catenary-type · CPC title