Subsea process assembly

• US 20050145388A1
• Filed: 03/24/2003
• Published: 07/07/2005
• Est. Priority Date: 04/08/2002
• Status: Active Grant

• Current Assignee: OneSubsea IP UK Limited (SLB)
• Original Assignee: Cooper Cameron Corporation (SLB)
• Inventors: Hopper, Hans Paul
• Granted Patent: US 7,152,682 B2
• Time in Patent Office: Days
• US Class Current: 166/357
• CPC Class Codes: B01D 17/00 Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion devices for separating or removing fatty or oily substances or similar floating material from water, waste water, or sewage C02F1/40; cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; arrangements for separating lubricants from refrigerants F25B43/02
• CPC Class Codes: B01D 17/0208 by sedimentation
• CPC Class Codes: B01D 17/0214 with removal of one of the phases
• CPC Class Codes: B01D 17/0217 by centrifugal force
• CPC Class Codes: B01D 17/044 by changing the pressure
• CPC Class Codes: B01D 17/06 Separation of liquids from each other by electricity
• CPC Class Codes: B01D 17/12 Auxiliary equipment particularly adapted for use with liquid-separating apparatus, e.g. control circuits
• CPC Class Codes: B01D 19/0057 the centrifugal movement being caused by a vortex, e.g. using a cyclone, or by a tangential inlet
• CPC Class Codes: B01D 21/10 Settling tanks with multiple outlets for the separated liquids
• CPC Class Codes: B01D 21/2411 having a tangential inlet
• CPC Class Codes: B01D 21/2427 The feed or discharge opening located at a distant position from the side walls
• CPC Class Codes: B01D 21/26 Separation of sediment aided by centrifugal force or centripetal forcecentrifuges B04B; cyclones B04C
• CPC Class Codes: E21B 43/017 Production satellite stations, i.e. underwater installations comprising a plurality of satellite well heads connected to a central station
• CPC Class Codes: E21B 43/36 Underwater separating arrangements E21B43/38 takes precedence
• CPC Class Codes: E21B 43/40 Separation associated with re-injection of separated materials E21B43/385 takes precedence

Abstract

A subsea process assembly for separating a multiphase flow, the assembly comprising: an inlet for a multiphase medium; a pressure reducing means for reducing the pressure of the multiphase flow from the inlet and creating a source of energy; a multiphase separator for separating the multiphase input into individual phases; and a pumping system for, in use, pumping at least one of the desired individual phases to a delivery point by utilizing at least some of the energy from the source of energy.

Claims

1. A subsea process assembly for separating a multiphase flow, the assembly comprising:

an inlet for a multiphase medium;

a pressure reducing means for reducing the pressure of the multiphase flow from the inlet and creating a source of energy;

a multiphase separator for separating the multiphase input into individual phases; and

a pumping system for, in use, pumping at least one of the desired individual phases to a delivery point by utilising of the energy from the source of energy.

2. A subsea process assembly according to claim 1, wherein the pressure reducing means is one of a hydraulic power device, electric power drive and a flow controller.

3. A subsea process assembly according to claim 1, further comprising a control process module for controlling the pressure reducing means and the pumping system.

4. A subsea process assembly according to claim 1, further comprising a power drive unit that generates hydraulic power from an external energy source.

5. A subsea process assembly according to claim 4, wherein the external energy source is either in the form of fluid or electrical energy.

6. A subsea process assembly according to claim 5, wherein the power drive unit and/or the pressure reducing means is driven by a fluid which provides energy in the form of liquid or gas.

7. A subsea process assembly according to claim 6, wherein the wellstream energy is achieved by creating a pressure differential in the multiphase flow between the inlet and the separator.

8. A subsea process assembly according to claim 1, further comprising a drive fluid inlet, the drive fluid being pumped to the module from an external point.

9. A subsea process assembly according to claim 1, wherein the pressure reducing means further comprises a means for creating a pressure differential in the drive fluid and thereby creating a further source of energy.

10. A subsea process assembly according to claim 4, wherein the drive fluid is water from a water injection supply.

11. A subsea process assembly according to claim 1, wherein the pressure of the multiphase flow is reduced to below 25 atmospheres.

12. A subsea process assembly according to claim 1, wherein the multistage separator can be formed by at least one of the following:

a centrifugal container, a vortex tube, a cyclone, helix container or auger, a gravity vertical or horizontal tank, a silo, a conductor pile housing, toroidal ring, a toroidal spiral combination or a spiral.

13. A subsea process assembly according to claim 1, wherein the separating process can separate the multiphase fluid into at least two of the following:

a solids slurry, gas, oil and water.

14. A subsea process assembly according to claim 1, further comprising an individual pump for each phase.

15. A subsea process assembly according to claim 14, wherein the individual phase pumps are driven by the energy created in the assembly.

16. A subsea process assembly according to claim 1 further comprising of a solids removal unit for removing a solids slurry prior to separation.

17. A subsea process assembly according to claim 1, further comprising a means for, in use, injecting exhaust water into a well.

18. A subsea process assembly according to claim 1, further comprising a template, a piping mat and a retrievable subsea process module.

19. A subsea process assembly according to claim 18, wherein the retrievable subsea process module comprises a retrievable base module and retrievable mini modules.

20. A subsea hydrocarbon recovery system comprising:

a subsea well for supplying a multiphase fluid;

a subsea process assembly comprising

an inlet for a multiphase medium;

a pressure reducing means for reducing the pressure of the multiphase flow from the inlet and creating a source of energy;

a multiphase separator for separating the multiphase input into individual phases; and

a pumping system for, in use pumping at least one of the desired individual phases to a delivery point by utilising of the energy from the source of energy, wherein the inlet to the assembly is in fluid communication with the well; and

a delivery point for receiving the recovered hydrocarbon(s) from the subsea process assembly.

21. A subsea hydrocarbon recovery system according to claim 20, further comprising a well into which surplus products of the separation can be reinjected.

22. A subsea hydrocarbon recovery system according to claim 20, further comprising a plurality of subsea wells, each having an associated subsea process module which supplies the recovered hydrocarbon(s) to the same delivery point.

23. A subsea hydrocarbon recovery system according to claim 20, wherein the delivery point is one of:

a pipeline for removing the product from the field, a water injection well, a gas injection well or a producing well to achieve artificial lift.