Remote heave compensation system

Patent metadata

Field	Value
Publication number	US-9290362-B2
Application number	US-201314105909-A
Country	US
Kind code	B2
Filing date	Dec 13, 2013
Priority date	Dec 13, 2012
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A remote heave compensation system associated with a crane on a vessel may include a heave compensator arranged remotely from the crane and configured to translate in association with and to compensate for heaving motion of the vessel, an equalizer arranged on the crane and coupled to an end of a multiline system of the crane, a heave line secured to the equalizer at a first end and secured to the heave compensator at a second end, wherein compensating motion of the heave compensator is transferred to the equalizer by the heave line to compensate for heaving motion of the vessel and stabilize objects suspended from the multiline system of the crane.

First claim

What is claimed is:

1. A remote heave compensation system comprising:
a heave compensator configured for arrangement at a remote location from a crane and configured to translate in association with and to compensate for heaving motion of a vessel supporting the crane;
an equalizer configured for arrangement on the crane and further configured for coupling to an end of a multiline lifting and lowering system of the crane; and
a heave line, separate from the multiline lifting and lowering system of the crane, secured to the equalizer at a first end, configured for extending along a portion of the crane and off of the crane to the remote location of the heave compensator, and secured to the heave compensator at a second end,
wherein, compensating motion of the heave compensator is transferred to the equalizer by the heave line to compensate for heaving motion of the vessel and stabilize objects suspended from the multiline lifting and lowering system of the crane.

2. The remote heave compensation system of claim 1 , wherein the multiline lifting and lowering system is a deep water lowering system.

3. The remote heave compensation system of claim 2 , wherein the deep water lowering system comprises a pair of line spools where each spool comprises an outgoing line extending up a boom of the crane, down to a load block and returning to the equalizer on the crane.

4. The remote heave compensation system of claim 3 , wherein a first of the outgoing lines is a right lay line and a second of the outgoing lines is a left lay line.

5. The remote heave compensation system of claim 1 , wherein the heave compensator comprises a heave line drum having a supply of heave line and a compensator sheave arranged along the heave line and configured for taking up or releasing heave line from the heave compensator.

6. The remote heave compensation system of claim 5 , wherein the compensator sheave is arranged on a rack and the heave line extends from the heave line drum, around the compensator sheave and generally passes back along the line extending to compensator sheave, wherein motion of the compensator sheave along the rack causes the taking up or releasing of the heave line.

7. The remote heave compensation system of claim 6 , wherein the heave line extending to the compensator sheave is generally parallel to the line leaving the heave line sheave such that an amount of heave line that is taken up or released is equal to approximately twice the amount of motion of the compensator sheave.

8. The remote heave compensation system of claim 1 , wherein the crane includes a central vertical axis about which the crane pivots and the heave line extends to the crane substantially parallel to and in close proximity to the central vertical axis.

9. The remote heave compensation system of claim 1 , wherein the equalizer comprises a pair of drums, each drum secured to one end of one of the lines of the multiline system.

10. The remote heave compensation system of claim 9 , wherein the lines are wrapped around the drums to induce rotational motion in each drum in a direction opposite to the other thereby equalizing the loads in the lines of the multiline system.

11. A crane having a heave compensation system, comprising:
a base;
a crane boom extending from the base;
a multiline system arranged on the crane for raising and lowering objects from the crane boom; and
a remote heave compensation system associated with the crane boom and comprising:
a heave compensator arranged at a remote location from the crane boom and configured to translate in association with and to compensate for heaving motion of a vessel;
an equalizer arranged on the crane boom and coupled to an end of the multiline system;
a heave line, separate from the multiline system of the crane, secured to the equalizer at a first end, extending along a portion of the crane boom and off of the crane boom to the remote location of the heave compensator, and secured to the heave compensator at a second end,

wherein, compensating motion of the heave compensator is transferred to the equalizer by the heave line to compensate for heaving motion of the vessel and stabilize objects suspended from the multiline system.

12. The crane of claim 11 , wherein the heave compensator comprises a heave line drum having a supply of heave line and a compensator sheave arranged along the heave line and configured for taking up or releasing heave line from the heave compensator.

13. The crane of claim 12 , wherein the compensator sheave is arranged on a rack and the heave line extends from the heave line drum, around the compensator sheave and generally passes back along the line extending to compensator sheave, wherein motion of the compensator sheave along the rack causes the taking up or releasing of the heave line.

14. The crane of claim 13 , wherein the heave line extending to the compensator sheave is generally parallel to the line leaving the heave line sheave such that an amount of heave line that is taken up or released is equal to approximately twice the amount of motion of the compensator sheave.

15. The crane of claim 11 , wherein the crane includes a central vertical axis about which the crane pivots and the heave line extends to the crane substantially parallel to and in close proximity to the central vertical axis.

16. The remote heave compensation system of claim 11 , wherein the equalizer comprises a pair of drums, each drum secured to one end of one of the lines of the multiline system.

17. The remote heave compensation system of claim 16 , wherein the lines are wrapped around the drums to induce rotational motion in each drum in a direction opposite to the other thereby equalizing the loads in the lines of the multiline system.

Assignees

• Nat Oilwell Varco Lp

Inventors

• Hey John E

Classifications

• B66C13/02 Primary

  Devices for facilitating retrieval of floating objects, e.g. for recovering crafts from water (handling live-boats B63B; salvaging, or hauling-out on slipways, waterborne vessels B63C; winding mechanism controls B66D1/52) · CPC title

• B66C13/04 Primary

  Auxiliary devices for controlling movements of suspended loads, or preventing cable slack · CPC title

• B66C23/53 Primary

  including counterweight or means to compensate for list, trim, or skew of the vessel or platform (counterweights or supports for balancing lifting couples B66C23/72; equipment to decrease unwanted vessel movements B63B39/00) · CPC title