Depressurisation method and apparatus for subsea equipment

• US 10,641,065 B2
• Filed: 04/25/2017
• Issued: 05/05/2020
• Est. Priority Date: 04/29/2016
• Status: Active Grant

• Current Assignee: Technip UK Ltd. (TechnipFMC, plc)
• Original Assignee: Forsys Subsea Limited
• Inventors: Espinasse, Philippe Francois, Parenteau, Thomas, Marret, Antoine
• Primary Examiner(s): Armstrong, Kyle
• Application Number:
  US16/095,992
• Publication Number:
  US 20190136671A1
• Time in Patent Office: 1,106 Days
• CPC Class Codes: E21B 43/01 specially adapted for obtaining from underwater installations
• CPC Class Codes: E21B 43/013 Connecting a production flow line to an underwater well head
• CPC Class Codes: F16L 2101/20 Expelling gases or fluids
• CPC Class Codes: F16L 2101/70 Drill-well operations
• CPC Class Codes: F16L 55/26 Pigs or moles, i.e. devices movable in a pipe or conduit with or without self-contained propulsion means

Abstract

A method for reducing the pressure of fluid within subsea equipment. The method includes the steps of: (a) providing a pipe, (b) laying the pipe on the sea floor, (c) providing a connector, (d) connecting the pipe to the subsea equipment via the connector, and (e) extracting fluid from the subsea equipment through the connector and into the pipe. Apparatus for reducing the pressure of fluid within subsea equipment by extracting fluid from the subsea equipment.

Claims

1. A method for reducing the pressure of fluid within subsea equipment, the method comprising the steps of:

(a) providing a flexible pipe, a pump connected to the flexible pipe, and a pig within the flexible pipe,

(b) laying the flexible pipe on the sea floor,

(c) providing a connector,

(d) connecting the flexible pipe to the subsea equipment via the connector,

(e) extracting fluid from the subsea equipment through the connector and into the flexible pipe,

(f) after step (e), pumping the fluid in the flexible pipe through the connector and to the subsea equipment by pushing the pig along the flexible pipe from a pig starting point to a pig finishing point.

2. The method as claimed in claim 1, wherein step (e) further comprises pumping the fluid from the subsea equipment through the connector and into the pipe.

3. The method as claimed in claim 1, wherein step (e) additionally comprises measuring the amount of fluid extracted from the subsea equipment through the connector and into the flexible pipe.

4. The method as claimed in claim 1, wherein step (e) additionally comprises adding a hydrate formation inhibitor to the fluid being extracted.

5. The method as claimed in claim 1, further comprising (g) recovering the flexible pipe to a topside vessel after step (f).