Device in a subsea system for controlling a hydraulic actuator and a subsea system with a hydraulic actuator

• US 6,729,130 B1
• Filed: 03/20/2002
• Issued: 05/04/2004
• Est. Priority Date: 09/30/1999
• Status: Expired due to Term

• Current Assignee: Fmc Kongsberg Subsea As (TechnipFMC, plc)
• Original Assignee: Fmc Kongsberg Subsea As (TechnipFMC, plc)
• Inventors: Lilleland, Svein
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Kershteyn, Igor
• Application Number:
  US10/088,652
• Time in Patent Office: 776 Days
• Field of Search: 604/19, 604/13, 603/29
• US Class Current: 60/413
• CPC Class Codes: E21B 33/0355 Control systems, e.g. hydraulic, pneumatic, electric, acoustic, for submerged well heads

Abstract

A device in a subsea system for controlling a hydraulic actuator (1) which is connected to a supply line (2) for supply of a supply fluid to the actuator (1) and a return line (3) for removal of a return fluid from the actuator. The device (10) include: a housing (11) and a body (29) which is movable in the housing (11), which together define a high-pressure chamber (14), which communicates with the supply line (2), and a low-pressure chamber (15), which communicates with the return line (3), and whose volume is a function of the pressure of the return fluid and the supply fluid.

Claims

1. A subsea system with a hydraulic actuator for operation of a process control device, in connection with recovery of hydrocarbons from a well, wherein the system comprises a supply line for supply of a supply fluid to the hydraulic actuator and a return line for removal of a return fluid from the hydraulic actuator;

the subsea system comprising a device for controlling the hydraulic actuator, the device comprising a housing and a body which is movable in the housing, and which together with the housing defines a low-pressure chamber, which communicates with the return line;

the housing and the body also defining a high-pressure chamber, which communicates with the supply line, whereby the body'"'"'s position and thereby the volume of the low-pressure chamber are a function of the pressure of the return fluid and the supply fluid.

2. The subsea system according to claim 1, wherein the housing and the body are components of a pressure converter.

3. The subsea system according to claim 1, wherein the high-pressure chamber has a first internal cross section, the low-pressure chamber has a second internal cross section, and the body comprises a piston, which is movable in the housing'"'"'s longitudinal direction, and which comprises a first piston portion with a cross section, which is adapted to the first internal cross section, the first piston portion being securely connected to a second piston portion, which has a cross section, which is adapted to the second internal cross section.

4. The subsea system according to claim 3, wherein the area of the second cross section is between 5 and 100 times larger than the area of the first cross section.

5. The subsea system according to claim 4, wherein the area of the second cross section is between 20 and 60 times larger than the area of the first cross section.

6. The subsea system according to claim 4, further comprising a main supply line which is directly or indirectly connected to the supply line, a main return line which is directly or indirectly connected to the return line, and wherein the main supply and main return lines are enveloped by an umbilical which connects a subsea production valve with a central unit.