Acid injection

Patent metadata

Field	Value
Publication number	US-10094200-B2
Application number	US-201414260423-A
Country	US
Kind code	B2
Filing date	Apr 24, 2014
Priority date	Apr 24, 2013
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A method of applying acid-wash to a subsea connection assembly, in particular a stabplate connection, in order to remove unwanted material such as marine growth and calcareous deposits. The method consists of inserting a plug, containing channels, into a central in a stabplate connection and injecting acid-wash through the plug. The plug may be carried by an operating tool arm of a remotely operated underwater vehicle (ROV).

First claim

What is claimed is:

1. A method of applying acid-wash to a subsea connection system,
wherein the subsea connection system comprises a removable plate attached by an attachment to a fixed plate to define a central opening, the method comprising:
inserting a plug, comprising at least one channel and a sealing ring, into the central opening to seal the central opening by the sealing ring, the attachment further defining a cavity with the sealing ring of the plug, such that the cavity, into which the acid-wash is injected, is adjacent to the sealed central opening;
sealing the cavity; and
subsequently, injecting the acid-wash into the at least one channel.

2. The method according to claim 1 , wherein the step of inserting the plug is carried out by a remotely operated underwater vehicle.

3. The method according to claim 2 , wherein the attachment defined cavity into which the acid-wash is injected, and wherein a surface of the remotely operated underwater vehicle abuts against the attachment to seal the cavity prior to the step of injecting the acid-wash into the at least one channel.

4. The method according to claim 1 , wherein the removable plate carries connectors mated with connectors carried by the fixed plate.

5. The method according to claim 4 , wherein the acid-wash is forced through channels in the removable plate to the connectors.

6. The method of claim 1 , wherein injecting the acid-wash is in a targeted manner.

7. A method of applying acid-wash to a subsea connection system, wherein the subsea connection system comprises a removable plate attached by an attachment to a fixed plate to define a central opening, the method comprising:
inserting a plug, comprising at least one channel and a sealing ring, into the central opening to seal the central opening by the sealing ring; and
injecting the acid-wash into the at least one channel, wherein:
the step of inserting the plug is carried out by a remotely operated underwater vehicle, and
the attachment with the sealing ring of the plug defines a cavity, such that the cavity, into which the acid-wash is injected, is adjacent to the sealed central opening, wherein a surface of the remotely operated underwater vehicle abuts against the attachment to seal the cavity prior to the step of injecting the acid-wash into the at least one channel.

8. The method according to claim 7 , wherein the removable plate carries connectors mated with connectors carried by the fixed plate.

9. The method according to claim 8 , wherein the acid-wash is forced through channels in the removable plate to the connectors.

10. The method of claim 7 , wherein injecting the acid-wash is in a targeted manner.

11. An apparatus, comprising:
a subsea connection system comprising a removable plate attached by an attachment to a fixed plate to define a central opening; and
a plug comprising at least one channel into which acid-wash is injected in use and a sealing ring to seal the central opening, a cavity defined by the attachment and the sealing ring of the plug into which the acid-wash can be injected and the cavity is adjacent to the sealed central opening; and wherein the cavity is sealed prior to injecting the acid-wash into the at least one channel.

12. The apparatus according to claim 11 , wherein a surface of a remotely operated underwater vehicle can abut against the attachment to seal the cavity prior to the injecting of the acid-wash into the at least one channel.

13. The apparatus according to claim 11 , wherein the removable plate carries connectors mated with connectors carried by the fixed plate.

14. The apparatus according to claim 13 , wherein the removable plate comprises channels through which acid-wash can be forced to the connectors.

15. A subsea structure incorporating the apparatus of claim 11 .

16. The apparatus according to claim 11 , wherein:
the plug is insertable into the central opening by a remotely operated underwater vehicle, and
a surface of the remotely operated underwater vehicle can abut against the attachment to seal the cavity prior to the injecting of the acid-wash into the at least one channel.

17. The apparatus according to claim 16 , wherein the removable plate carries connectors mated with connectors carried by the fixed plate.

18. The method of claim 11 , wherein the acid-wash is injected in a targeted manner.

Assignees

• Vetco Gray Controls Ltd
• Ge Oil & Gas Uk Ltd

Inventors

• Vangasse Anthony Jason
• Lewis Gareth Huw

Classifications

• E21B41/0007 Primary

  for underwater installations (E21B41/005, E21B41/04, E21B41/06, E21B41/08, E21B41/10 take precedence) · CPC title

• E21B33/038

  Connectors used on well heads, e.g. for connecting blow-out preventer and riser · CPC title

• E21B37/06 Primary

  using chemical means for preventing or limiting {, e.g. eliminating,} the deposition of paraffins or like substances · CPC title