Control and supply system

• US 8,212,378 B2
• Filed: 08/14/2009
• Issued: 07/03/2012
• Est. Priority Date: 10/30/2000
• Status: Active Grant

• Current Assignee: Onesubsea IP UK Limited (Schlumberger NV)
• Original Assignee: Cameron International Corporation (Schlumberger NV)
• Inventors: Biester, Klaus, Kunow, Peter
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US12/541,227
• Publication Number:
  US 20090296428A1
• Time in Patent Office: 1,054 Days
• Field of Search: 307/1, 307/3, 307/4
• US Class Current: 307/1
• CPC Class Codes: H02J 2310/12 The local stationary network supplying a household or a building
• CPC Class Codes: H02J 3/36 Arrangements for transfer of electric power between ac networks via a high-tension dc link
• CPC Class Codes: Y02E 60/60 Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
• CPC Class Codes: Y02P 80/14 District level solutions, i.e. local energy networks

Abstract

In accordance with at least some embodiments, a maritime well system includes a sea-surface control unit. The maritime well system also includes a sea-bed control unit coupled to the sea-surface control unit by a sub-sea cable configured to carry a direct current (DC) voltage output from the sea-surface control unit at least 30 kilometers to the sea-bed control unit. The maritime well system also includes a sub-sea tree coupled to the sea-bed control unit via a connecting line configured to carry a converted voltage output from the sea-bed control unit to the sub-sea tree. In accordance with at least some embodiments, the cross-sectional area of the sub-sea cable is designed to carry a predetermined amount of power to the sea-bed control unit as DC power and is at least 10 times smaller than a cross-sectional area needed for carrying the predetermined amount of power to the sea-bed control unit as alternating current (AC) power.

Claims

1. A maritime well system, comprising:

a sea-surface control unit;

a sea-bed control unit coupled to the sea-surface control unit by a sub-sea cable configured to carry a direct current (DC) voltage output from the sea-surface control unit at least 30 kilometers to the sea-bed control unit, wherein the sea-bed control unit produces a reduced converted voltage from the DC voltage; and

a sub-sea tree coupled to the sea-bed control unit via a connecting line configured to carry the reduced converted voltage output from the sea-bed control unit to the sub-sea tree, wherein the sub-sea tree comprises a plurality of electrical devices and wherein the connecting line directly couples the reduced converted voltage to a least one of the plurality of electrical devices;

wherein the DC voltage output is at least 3000V for transmission via the sub-sea cable to the sea-bed control unit and wherein the reduced converted voltage output is at least 240V for transmission via the connecting line to the sub-sea tree.

2. The maritime well system of claim 1 wherein a cross-sectional area of the sub-sea cable is designed to carry a predetermined amount of power to the sea-bed control unit as DC power and is at least 10 times smaller than a cross-sectional area needed for carrying the predetermined amount of power to the sea-bed control unit as alternating current (AC) power.

3. The maritime well system of claim 1 wherein a cross-sectional area of the sub-sea cable is designed to carry a predetermined amount of power to the sea-bed control unit as DC power and is at least 25 times smaller than a cross-sectional area needed for carrying the predetermined amount of power to the sea-bed control unit as alternating current (AC) power.

4. The maritime well system of claim 1 wherein a cross-sectional area of the sub-sea cable is designed to carry a predetermined amount of power to the sea-bed control unit as DC power and is at least 5 times smaller than a cross-sectional area needed for carrying the predetermined amount of power to the sea-bed control unit as alternating current (AC) power with power factor correction.

5. The maritime well system of claim 1 further comprising a multiplexer and a data coupler at the sea surface, wherein the multiplexer and the data coupler selectively modulate data onto the DC voltage output from sea-surface control unit.

6. The maritime well system of claim 1 wherein the sub-sea tree comprises a motor-actuated valve that operates by receiving the reduced converted voltage output in a range between 240V to 300V.

7. The maritime well system of claim 1 wherein the sub-sea control unit comprises a measurement device and a data modulation device to transmit data to the sea-surface control unit for regulating the DC voltage output.

8. The maritime well system, comprising:

a sea-surface control unit;

a sea-bed control unit coupled to the sea-surface control unit by a sub-sea cable configured to carry a direct current (DC) voltage output from the sea-surface control unit at least 30 kilometers to the sea-bed control unit;

a sub-sea tree coupled to the sea-bed control unit via a connecting line configured to carry a converted voltage output from the sea-bed control unit to the sub-sea tree; and

a data transmission device coupled to the sea-surface control unit, wherein control and monitoring of all components of the maritime well system occur through the data transmission device.

9. A method for a maritime well system, comprising:

providing a sea-surface control unit;

coupling a sea-bed control unit to the sea-surface control unit using a sub-sea cable configured to carry a direct current (DC) voltage output from the sea-surface control unit at least 30 kilometers to the sea-bed control unit, wherein the sea-bed control unit produces a reduced converted voltage from the DC voltage and the reduced converted voltage directly actuates at least one of a plurality of electrical devices of a sub-sea tree;

coupling the sub-sea tree to the sea-bed control unit via a connecting line configured to carry the reduced converted voltage output from the sea-bed control unit to the sub-sea tree; and

transmitting the DC voltage output in a range between 3000V to 6000V via the sub-sea cable to the sea-bed control unit and transmitting the reduced converted DC voltage output in a range between 240V to 300V via the connecting line to the sub-sea tree.

10. The method of claim 9 further comprising selecting a cross-sectional area of the sub-sea cable to carry a predetermined amount of power to the sea-bed control unit as DC power and to be at least 10 times smaller than a cross-sectional area needed for carrying the predetermined amount of power to the sea-bed control unit as alternating current (AC) power.

11. The method of claim 9 further comprising selecting a cross-sectional area of the sub-sea cable to carry a predetermined amount of power to the sea-bed control unit as DC power and to be at least 25 times smaller than a cross-sectional area needed for carrying the predetermined amount of power to the sea-bed control unit as alternating current (AC) power.

12. The method of claim 9 further comprising selecting a cross-sectional area of the sub-sea cable to carry a predetermined amount of power to the sea-bed control unit as DC power and to be at least 5 times smaller than a cross-sectional area needed for carrying the predetermined amount of power to the sea-bed control unit as alternating current (AC) power with power factor correction.

13. The method of claim 9 further comprising selectively coupling data onto the DC voltage output at the sea surface.

14. The method of claim 9 further comprising operating a motor-actuated valve of the sub-sea tree by providing the reduced converted voltage output in a range between 240V to 300V to the motor-actuated valve.

15. The method of claim 9 further comprising providing data from the sub-sea control unit to the sea-surface control unit to regulate the DC voltage output.

16. A method for a maritime well system comprising:

providing a sea-surface control unit;

coupling a sea-bed control unit to the sea-surface control unit using a sub-sea cable configured to carry a direct current (DC) voltage output from the sea-surface control unit at least 30 kilometers to the sea-bed control unit;

coupling a sub-sea tree to the sea-bed control unit via a connecting line configured to carry a converted voltage output from the sea-bed control unit to the sub-sea tree; and

controlling and monitoring all components of the maritime well system using a data transmission device.

17. A maritime well system, comprising:

a sea-surface control unit;

a sea-bed control unit coupled to the sea-surface control unit by a sub-sea cable configured to carry a direct current (DC) voltage output from the sea-surface control unit to the sea-bed control unit, wherein the sea-bed control unit produces a reduced converted voltage from the DC voltage; and

a sub-sea tree coupled to the sea-bed control unit via a connecting line configured to carry the reduced converted voltage output from the sea-bed control unit to the sub-sea tree,

wherein a cross-sectional area of the sub-sea cable is designed to carry a predetermined amount of power to the sea-bed control unit as DC power and is at least 10 times smaller than a cross-sectional area needed for carrying the predetermined amount of power to the sea-bed control unit as alternating current (AC) power; and

wherein the DC voltage output is at least 3000V for transmission via the sub-sea cable to the sea-bed control unit and wherein the reduced converted voltage output is at least 240V for transmission via the connecting line to the sub-sea tree and wherein the connecting line directly couples the reduced converted voltage to a motor-actuated valve of the sub-sea tree.