System and method of pressure reduction and drainage of annulus of flexible pipes

Patent metadata

Field	Value
Publication number	US-12060770-B2
Application number	US-202017782834-A
Country	US
Kind code	B2
Filing date	Nov 24, 2020
Priority date	Dec 5, 2019
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

The invention presents a system and method for reducing pressure and draining the annulus of submerged flexible pipes, with application in all flexible pipe structures and in any industry that uses these types of pipes. Its objectives are to eliminate condensed water and reduce the partial pressure of CO2, thus restoring the integrity of the pipes. In addition, with the reduction of the pressure of the annulus gases, the operations of collection of the pipes can be carried out with greater speed, that is, in less time. The previous relief of the annulus pressure further reduces the risk of rupture of the outer cap during the operation, thus reducing the risk of exposing operators to the presence of harmful gases, when the pipe reaches the deck of the PLSV vessel.

First claim

The invention claimed is:

1. A system comprising:
a flexible pipe connector;
a device configured to cause pressure reduction and drainage of an annulus of at least one flexible pipe connected to the flexible pipe connector, the device comprising:
a cylinder that is configured to connect to a relief valve of the flexible pipe connector;
a seal that is configured to seal the cylinder to the flexible pipe connector;
a plunger within the cylinder;
a hydraulic actuator comprising a rod that is configured actuate the plunger;
a valve;
a hose;
a vacuum pump connected to the valve via the hose; and
a pressure gauge configured to provide a pressure reading indicating whether the cylinder is sealed to the flexible pipe connector in a state where the plunger is actuated,

wherein the valve is configured to open such as to cause a chamber of the cylinder to be in fluid communication with the hose.

2. The system according to claim 1 , further comprising a manipulator of a remotely operated vehicle (ROV), the manipulator configured to move the device to the flexible pipe connector.

3. The system according to claim 2 , further comprising claws that are attached to the manipulator, the claws configured to embrace the flexible pipe connector and install the device in a recess of the relief valve of the flexible pipe connector, such that the cylinder is configured to seal against a recess wall of the relief valve.

4. The system according to claim 3 , wherein the claws are configured to be hydraulically actuated based on control by the ROV.

5. The system according to claim 4 , wherein the manipulator is connected to the claws via a handle, and the manipulator is configured to operate the claws via the handle.

6. A method comprising:
sealing a cylinder of a device to a flexible pipe connector;
actuating a plunger within the cylinder by controlling a hydraulic actuator, of the device, that includes a rod configured to actuate the plunger;
determining that the cylinder is sealed to the flexible pipe connector based on a pressure reading, of a pressure gauge of the device, that is obtained while actuating the plunger;
reducing pressure of an annulus of at least one flexible pipe connected to the flexible pipe connector to atmospheric pressure based on the determining, the reducing the pressure comprising opening a valve of the device, the valve connected to a hose;
closing the valve after opening the valve;
unsealing the cylinder from the flexible pipe connector after the reducing the pressure; and
removing the device from the flexible pipe connector after the unsealing.

7. The method according to claim 6 , wherein the valve is configured to open such as to cause a chamber of the cylinder to be in fluid communication with the hose, and the hose is at atmospheric pressure during the opening of the valve.

8. The method of claim 6 , further comprising automatically closing a relief valve of the flexible pipe connector when the pressure of the annulus becomes equal to the atmospheric pressure.

9. The method of claim 8 , wherein the relief valve is configured to cause the pressure of the annulus to be equal to the atmospheric pressure.

10. The method of claim 6 , wherein
the valve is connected to a vacuum pump via the hose, and
the reducing the pressure further comprises operating the vacuum pump while the valve is opened.

11. The method of claim 10 , wherein the vacuum pump, by being operated, is configured to cause the pressure in the annulus to reduce such that condensed water is removed from the annulus.

Assignees

• Petroleo Brasileiro Sa Petrobras
• Petroleo Brasileiro S A —Petrobras

Inventors

• Santos Poli Paulo Roberto
• Maia De Souza Carlos Eduardo
• Carneiro Campello George

Classifications

• F16L11/08

  with reinforcements embedded in the wall (F16L11/11 takes precedence) · CPC title

• E21B41/04

  Manipulators for underwater operations, e.g. temporarily connected to well heads · CPC title

• E21B43/013 Primary

  Connecting a production flow line to an underwater well head · CPC title

• G01M3/2815

  using pressure measurements · CPC title

• G01L7/18

  using liquid as the pressure-sensitive medium, e.g. liquid-column gauges · CPC title