PASSIVE HEAVE COMPENSATOR

• US 20150362039A1
• Filed: 02/05/2014
• Published: 12/17/2015
• Est. Priority Date: 02/07/2013
• Status: Active Grant

• Current Assignee: Technip France (Technip)
• Original Assignee: Technip France (Technip)
• Inventors: CANNELL, David, LABBE, Christophe, ODIGIE, Eric, RIDDELL, Shaun
• Granted Patent: US 9,702,428 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B63B 39/03 by transferring liquids
• CPC Class Codes: B66C 13/10 for preventing cable slack control devices for rope, cable, or chain winding mechanisms, e.g. for controlling tensions, B66D1/40
• CPC Class Codes: B66C 23/53 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 Class Codes: E21B 19/002 specially adapted for underwater drilling E21B19/09, E21B19/143 take precedence
• CPC Class Codes: E21B 19/006 including heave compensators
• CPC Class Codes: F16F 2222/06 Magnetic or electromagnetic
• CPC Class Codes: F16F 2224/045 magnetorheological
• CPC Class Codes: F16F 9/535 Magnetorheological [MR] fluid dampers springs comprising magnetorheological [MR] elastomers F16F1/361

Abstract

A passive heave compensator having: a main hydraulic cylinder, including a moveable piston having a piston rod extendible through the main hydraulic cylinder and a piston head to divide the main hydraulic cylinder between a gas phase above the piston head, and oil phase below the piston head; an upper connection point associated with the main hydraulic cylinder and a lower connection point associated with the piston rod; and an accumulator having a moveable separator to divide the accumulator between a gas phase above the separator, and an oil phase below the separator and being in communication with the oil phase in the main hydraulic cylinder; wherein an oil phase includes a magnetorheological substance, and that the passive heave compensator includes one or more electromagnetic controllers. In this way, operation of the one or more electromagnetic controllers can magnetise the magnetorheological substance to vary the viscosity of the oil phase, thus changing the degree of damping that can be provided by the passive heave compensator.

Claims

1. A passive heave compensator comprising:

a main hydraulic cylinder, including a moveable piston having a piston rod extendible through the main hydraulic cylinder and a piston head to divide the main hydraulic cylinder between a gas phase above the piston head, and oil phase below the piston head;

an upper connection point associated with the main hydraulic cylinder and a lower connection point associated with the piston rod; and

an accumulator having a moveable separator to divide the accumulator between a gas phase above the separator, and an oil phase below the separator and being in communication with the oil phase in the main hydraulic cylinder;

wherein an oil phase includes a magnetorheological substance, and that the passive heave compensator includes one or more electromagnetic controllers.

2. A passive heave compensator as claimed in claim 1 wherein the magnetorheological substance comprises iron particles and oil.

3. A passive heave compensator as claimed in claim 1, wherein an electromagnetic controller is a variable electromagnet.

4. A passive heave compensator as claimed in claim 3 wherein the electromagnet is located in the oil phase of the main hydraulic cylinder.

5. A passive heave compensator as claimed in claim 3 wherein the passive heave compensator includes a passageway for communication of the oil phases between the main cylinder and accumulator, and wherein the electromagnet is located on or around said passageway.

6. A passive heave compensator as claimed in claim 1, wherein the one or more electromagnetic controllers are controllable by a remote operator.

7. A passive heave compensator as claimed in claim 6 wherein the remote operator is in an ROV or remote cage.

8. A passive heave compensator as claimed in claim 1, wherein the one or more electromagnetic controllers are controllable by a stand alone system mounted on or in the compensator.

9. A passive heave compensator as claimed in claim 6, wherein control of the one or more electromagnetic controllers is by a control module, a command module or both.

10. A passive heave compensator as claimed in claim 1, wherein the one or more electromagnetic controllers are controllable by relays along the lifting wire attached to the upper connection point.

11. A passive heave compensator as claimed in claim 1, wherein the one or more electromagnetic controllers are variable.

12. A passive heave compensator as claimed in claim 1, wherein the one or more electromagnetic controllers provide sea-depth pressure compensation.

14. A method of providing variable compensation to a passive heave compensator as defined in claim 1, comprising the steps of:

(a) providing loading to the passive heave compensator through the lower connection point;

(b) operating an electromagnetic controller to vary the viscosity of the oil phase of at least the main hydraulic cylinder.

15. A method as claimed in claim 14 for providing real time variable compensation to the passive heave compensator, further comprising the step of:

(c) monitoring the status of the loading on the passive heave compensator in real time and controlling the operation of the electromagnetic controller to contemporaneously vary the viscosity of the oil phase.

13. A passive heave compensator comprising:

a main hydraulic cylinder, including a moveable piston having a piston rod extendible through the main hydraulic cylinder and a piston head to divide the main hydraulic cylinder between a gas phase above the piston head, and oil phase below the piston head;

an upper connection point associated with the main hydraulic cylinder and a lower connection point associated with the piston rod; and

an accumulator having a moveable separator to divide the accumulator between a gas phase above the separator, and an oil phase below the separator and being in communication with the oil phase in the main hydraulic cylinder;

wherein the viscosity of the oil phase in at least the main hydraulic cylinder is variable.