SUBSEA FLOW LINE PLUG REMEDIATION

• US 20100047022A1
• Filed: 08/20/2008
• Published: 02/25/2010
• Est. Priority Date: 08/20/2008
• Status: Abandoned Application

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Le Moign, Yves
• Application Number:
  US12/194,562
• Publication Number:
  US 20100047022A1
• Time in Patent Office: Days
• US Class Current: 405/184.100
• CPC Class Codes: E02F 3/907 Measuring or control devices, e.g. control units, detection means or sensors E02F3/902 takes precedence
• CPC Class Codes: E02F 7/005 conveying material from the underwater bottom by pipelines E02F7/10; suction dredgers E02F3/88
• CPC Class Codes: E21B 17/01 Risers
• CPC Class Codes: E21B 37/06 using chemical means for preventing or limiting , e.g. eliminating, the deposition of paraffins or like substances

Abstract

A technique enables removal of a hydrate plug or other similar plug from a deep water flow line. When the existence of a plug in the deep water flow line is determined, a temporary flow line loop is created to enable remedial procedures. The temporary loop can be created by deploying a spoolable compliant guide and connecting the spoolable compliant guide to the deep water flow line. The connection is made in a manner that enables access to both sides of the unwanted plug.

Claims

1. A method for removing a hydrate plug from a deep water flow line, comprising:

determining the existence of a hydrate plug in a deep water flow line;

creating a temporary loop that includes a section of the deep water flow line containing the hydrate plug;

pumping a hydrate plug treatment fluid along the temporary loop to the hydrate plug; and

controlling pressure acting on both sides of the hydrate plug to facilitate a controlled removal of the hydrate plug.

2. The method as recited in claim 1, wherein creating a temporary loop comprises temporarily connecting a spoolable compliant guide to the deep water flow line on an opposite side of the hydrate plug from a surface production installation.

3. The method as recited in claim 1, wherein pumping comprises injecting methanol into the deep water flow line proximate to the hydrate plug.

4. The method as recited in claim 2, wherein pumping comprises injecting methanol through an interior of the spoolable compliant guide.

5. The method as recited in claim 4, further comprising deploying a coiled tubing within the spoolable compliant guide to deliver the methanol along the interior of the spoolable compliant guide.

6. The method as recited in claim 5, further comprising using the coiled tubing to deliver a fluid selected to reduce hydrostatic pressure in the spoolable compliant guide and in the deep water flow line to which the spoolable compliant guide is connected.

7. The method as recited in claim 1, wherein controlling pressure comprises selectively balancing pressure on both sides of the hydrate plug.

8. The method as recited in claim 2, wherein creating comprises coupling the spoolable compliant guide to an end termination unit of the deep water flow line.

9. The method as recited in claim 2, wherein creating comprises coupling the spoolable compliant guide to a wellhead tree of a well coupled to the deep water flow line.

10. A method, comprising:

temporarily coupling a spoolable compliant guide to a deep water flow line on an opposite side of a plug relative to a surface production installation;

removing the plug from the deep water flow line; and

disconnecting and retrieving the spoolable compliant guide.

11. The method as recited in claim 10, wherein temporarily coupling comprises temporarily coupling the spoolable compliant guide to an end termination unit of the deep water flow line.

12. The method as recited in claim 10, wherein temporarily coupling comprises temporarily coupling the spoolable compliant guide to a manifold of the deep water flow line.

13. The method as recited in claim 10, wherein temporarily coupling comprises temporarily coupling the spoolable compliant guide to a wellhead tree.

14. The method as recited in claim 10, wherein removing the plug comprises removing a hydrate plug.

15. The method as recited in claim 10, furthermore comprising, deploying a coiled tubing through the spoolable compliant guide to deliver plug removal fluid.

16. The method as recited in claim 10, further comprising controlling pressure acting on the plug on both sides of the plug.

17. A system, comprising:

a surface production installation;

a deep water flow line in fluid communication with the surface production installation; and

a spoolable compliant guide that may be selectively deployed to the deep water flow line to create a selected, temporary flow line loop of a variety of possible flow line loops to facilitate removal of a plug.

18. The system as recited in claim 17, wherein the deep water flow line comprises at least one end termination unit to which the spoolable compliant guide can be temporarily connected.

19. The system as recited in claim 17, wherein the deep water flow line is connected to a wellhead to which the spoolable compliant guide can be temporarily connected.

20. The system as recited in claim 17, further comprising a coiled tubing deployed within the spoolable compliant guide to deliver plug removal fluids.

21. The system as recited in claim 17, wherein the spoolable compliant guide comprises an isolation mechanism.

22. The system as recited in claim 17, wherein the spoolable compliant guide comprises an emergency disconnect.

23. The system as recited in claim 17, wherein the spoolable compliant guide is deployed in an S-shape to enable a vertical connection with the deep water flow line.

24. The system as recited in claim 17, wherein the spoolable compliant guide is deployed in a J-shape to enable a horizontal connection with the deep water flow line.