DEPRESSURISATION METHOD AND APPARATUS FOR SUBSEA EQUIPMENT

• US 20190136671A1
• Filed: 04/25/2017
• Published: 05/09/2019
• 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
• Granted Patent: US 10,641,065 B2
• Time in Patent Office: 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 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.

2. The method as claimed in claim 1, wherein the pipe is a flexible pipe.

3. The method as claimed in claim 1, wherein a pump is provided which is connected to the pipe, and step (e) comprises pumping the fluid from the subsea equipment through the connector and into the pipe.

4. The method as claimed in claim 1, wherein a pump is provided which is connected to the pipe, and the method additionally comprises after step (e) the following step:

(f) pumping the fluid in the pipe through the connector in order to return it to the subsea equipment.

5. The method as claimed in claim 4, wherein a pig is provided within the pipe and step (f) comprises pushing the pig along the pipe from a pig starting point to a pig finishing point.

6. 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 pipe.

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

12. The apparatus as claimed in claim 1, wherein the pipe has a first downstream end and a second upstream end and wherein an extraction pump for extracting fluid from the subsea equipment is provided downstream of the pipe.

13. The apparatus as claimed in claim 12, wherein a second closable opening is provided upstream of the extraction pump and downstream of the pipe.

8. An apparatus for reducing the pressure of fluid within subsea equipment arranged on the sea floor by extracting fluid from the subsea equipment, the apparatus comprising:

(a) a pipe laid on the sea floor for containing fluid extracted from the subsea equipment,

(b) a connector for providing fluid communication between the fluid in the subsea equipment and the pipe, and

(c) a valve for controlling the fluid communication between the subsea equipment through the connector and into the pipe.

9. The apparatus as claimed in claim 8, wherein the apparatus additionally comprises:

(d) a pig within the pipe which is transportable along the pipe in order to return the fluid in the pipe through the connector to the subsea equipment, and

(e) a pump for transporting the pig along the pipe.

10. The apparatus as claimed in claim 9, wherein the pipe has a first downstream end and a second upstream end and wherein the pump for transporting the pig is provided upstream of the pipe.

11. The apparatus as claimed in claim 9, wherein the pump for transporting the pig is a water pump and comprises a water inlet for drawing water into the pump so that it can be pumped downstream.

14. The apparatus as claimed in claim 8, wherein a flow meter is provided upstream of the valve.

15. The apparatus as claimed in claim 8, wherein the apparatus comprises an injector for adding a hydrate formation inhibitor to the fluid.