GB2174105A - Cleaning subsea surfaces - Google Patents

Cleaning subsea surfaces Download PDF

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Publication number
GB2174105A
GB2174105A GB08605927A GB8605927A GB2174105A GB 2174105 A GB2174105 A GB 2174105A GB 08605927 A GB08605927 A GB 08605927A GB 8605927 A GB8605927 A GB 8605927A GB 2174105 A GB2174105 A GB 2174105A
Authority
GB
United Kingdom
Prior art keywords
jet
cleaning
subsea
water
sea
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08605927A
Other versions
GB8605927D0 (en
GB2174105B (en
Inventor
Tony James Sidney Green
Stephen Geoffrey Drake
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
OILFIELD INSPECTION SERVICES
Original Assignee
OILFIELD INSPECTION SERVICES
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB858506255A external-priority patent/GB8506255D0/en
Priority claimed from GB08517343A external-priority patent/GB2164841B/en
Application filed by OILFIELD INSPECTION SERVICES filed Critical OILFIELD INSPECTION SERVICES
Priority to GB8605927A priority Critical patent/GB2174105B/en
Publication of GB8605927D0 publication Critical patent/GB8605927D0/en
Publication of GB2174105A publication Critical patent/GB2174105A/en
Application granted granted Critical
Publication of GB2174105B publication Critical patent/GB2174105B/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B7/00—Cleaning by methods not provided for in a single other subclass or a single group in this subclass
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
    • B08B3/02—Cleaning by the force of jets or sprays
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F1/00—Electrolytic cleaning, degreasing, pickling or descaling

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Cleaning By Liquid Or Steam (AREA)
  • Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)

Abstract

A method for cleaning a subsea structure in which a jet of sea-water is directed from an electrode (11) on to an adjacent subsea structure (10) while applying an electric voltage between the electrode and the structure, the jet pressure and the electric current being such as to remove material from the surface of the structure. If desired, abrasive material may be injected into the jet. The jet may be scanned over the structure. The nozzle 11 may be insulated except at the face from which the water emerges and may have an insulating skirt 14. <IMAGE>

Description

SPECIFICATION Cleaning subsea surfaces This invention is concerned with a method and apparatus for cleaning subsea surfaces.
It is known to machine workpieces by electrochemical machining. In electrochemical machining, a liquid electrolyte, e.g. sea water, may be passed between the surface of a metal workpiece and a tool electrode while a D.C. voltage is applied across electrolyte in the gap between tool and workpiece so that metal is removed from the workpiece.
It is an object of the present invention to provide an improved method and apparatus for cleaning subsea surfaces.
The invention provides a method of cleaning a subsea structure in which a jet of sea-water is directed from an electrode on to an adjacent subsea structure while applying an electric voltage between the electrode and the structure, the jet pressure and the electric current being such as to remove material from the surface of the structure.
From another aspect, the invention provides a method for cleaning a subsea surface of an electrically-conductive object comprising subjecting the surface to the action of a jet of negatively charged electrolyte so that material is removed from the surface by electrolytic action.
The jet is preferably scanned over the surface or structure.
If desired, more than one jet may be provided.
It may sometimes be advantageous to inject abrasive material into the jet.
The invention also provides apparatus for carrying out the methods set out above.
The following is a description, by way of example only, of an embodiment of the invention, reference being made to the accompanying schematic drawings in which Figures 1 and 2 illustrate respectively plan and side views of cleaning apparatus operating in accordance with the invention.
In the drawings, a steel subsea pipe 10 is being cleaned by high pressure sea water supplied through inlet 13 and emerging from water nozzle 11 which is connected to the negative terminal of a D.C. power supply unit 12, the positive terminal of which is connected to the pipe 10. The nozzle 11 is insulated over its entire surface except at the face from which the water emerges. The necessary stand-off (e.g. 5 mm) between the nozzle and the pipe may be provided by an insulating skirt 14.
Thus, material is removed from the pipe by electrolytic action as in electrochemical machining.
The water jet emerging from the nozzle is scanned over the surface of the pipe.
Abrasive material in particulate form may be injected into the jet to aid surface cleaning and the removal of non-metallic debris.
l 1. A method of cleaning a subsea structure in which a jet of sea-water is directed from an electrode on to an adjacent subsea structure while applying an electric voltage between the electrode and the structure, the jet pressure and the electric current being such as to remove material from the surface of the structure.
2. A method for cleaning a subsea surface of an electrically-conductive object comprises subjecting the surface to the action of a jet of negatively charged electrolyte so that material is removed from the surface by electrolytic action.
3. A method according to claim 1 or claim 2 wherein the jet is scanned over the surface or structure.
4. A method according to any preceding claim wherein abrasive material is injected into the jet.
5. A method cleaning a sub-sea structure substantially as hereinbefore described with reference to the accompanying drawings.
6. Apparatus for cleaning a sub-sea structure substantially as hereinbefore described with reference to the accompanying drawings.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Cleaning subsea surfaces This invention is concerned with a method and apparatus for cleaning subsea surfaces. It is known to machine workpieces by electrochemical machining. In electrochemical machining, a liquid electrolyte, e.g. sea water, may be passed between the surface of a metal workpiece and a tool electrode while a D.C. voltage is applied across electrolyte in the gap between tool and workpiece so that metal is removed from the workpiece. It is an object of the present invention to provide an improved method and apparatus for cleaning subsea surfaces. The invention provides a method of cleaning a subsea structure in which a jet of sea-water is directed from an electrode on to an adjacent subsea structure while applying an electric voltage between the electrode and the structure, the jet pressure and the electric current being such as to remove material from the surface of the structure. From another aspect, the invention provides a method for cleaning a subsea surface of an electrically-conductive object comprising subjecting the surface to the action of a jet of negatively charged electrolyte so that material is removed from the surface by electrolytic action. The jet is preferably scanned over the surface or structure. If desired, more than one jet may be provided. It may sometimes be advantageous to inject abrasive material into the jet. The invention also provides apparatus for carrying out the methods set out above. The following is a description, by way of example only, of an embodiment of the invention, reference being made to the accompanying schematic drawings in which Figures 1 and 2 illustrate respectively plan and side views of cleaning apparatus operating in accordance with the invention. In the drawings, a steel subsea pipe 10 is being cleaned by high pressure sea water supplied through inlet 13 and emerging from water nozzle 11 which is connected to the negative terminal of a D.C. power supply unit 12, the positive terminal of which is connected to the pipe 10. The nozzle 11 is insulated over its entire surface except at the face from which the water emerges. The necessary stand-off (e.g. 5 mm) between the nozzle and the pipe may be provided by an insulating skirt 14. Thus, material is removed from the pipe by electrolytic action as in electrochemical machining. The water jet emerging from the nozzle is scanned over the surface of the pipe. Abrasive material in particulate form may be injected into the jet to aid surface cleaning and the removal of non-metallic debris. CLAIMS l
1. A method of cleaning a subsea structure in which a jet of sea-water is directed from an electrode on to an adjacent subsea structure while applying an electric voltage between the electrode and the structure, the jet pressure and the electric current being such as to remove material from the surface of the structure.
2. A method for cleaning a subsea surface of an electrically-conductive object comprises subjecting the surface to the action of a jet of negatively charged electrolyte so that material is removed from the surface by electrolytic action.
3. A method according to claim 1 or claim 2 wherein the jet is scanned over the surface or structure.
4. A method according to any preceding claim wherein abrasive material is injected into the jet.
5. A method cleaning a sub-sea structure substantially as hereinbefore described with reference to the accompanying drawings.
6. Apparatus for cleaning a sub-sea structure substantially as hereinbefore described with reference to the accompanying drawings.
GB8605927A 1985-03-11 1986-03-11 Cleaning subsea surfaces Expired GB2174105B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8605927A GB2174105B (en) 1985-03-11 1986-03-11 Cleaning subsea surfaces

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB858506255A GB8506255D0 (en) 1985-03-11 1985-03-11 Electrochemical machining
GB08517343A GB2164841B (en) 1984-07-11 1985-07-09 Cleaning subsea surfaces
GB8605927A GB2174105B (en) 1985-03-11 1986-03-11 Cleaning subsea surfaces

Publications (3)

Publication Number Publication Date
GB8605927D0 GB8605927D0 (en) 1986-04-16
GB2174105A true GB2174105A (en) 1986-10-29
GB2174105B GB2174105B (en) 1989-06-21

Family

ID=27262614

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8605927A Expired GB2174105B (en) 1985-03-11 1986-03-11 Cleaning subsea surfaces

Country Status (1)

Country Link
GB (1) GB2174105B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2319259A (en) * 1996-11-15 1998-05-20 Babcock Rosyth Defence Limited reducing radionucleide contamination of a metallic component
WO2000068070A1 (en) * 1999-05-07 2000-11-16 Dennis Mason Method and apparatus for removing marine organisms from a submerged substrate
WO2015041538A1 (en) * 2013-09-17 2015-03-26 Jupa As Acid block and method of local acid treatment of subsea connecting element

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2164841A (en) * 1984-07-11 1986-04-03 Oilfields Inspection Services Cleaning subsea surfaces

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2164841A (en) * 1984-07-11 1986-04-03 Oilfields Inspection Services Cleaning subsea surfaces

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2319259A (en) * 1996-11-15 1998-05-20 Babcock Rosyth Defence Limited reducing radionucleide contamination of a metallic component
WO2000068070A1 (en) * 1999-05-07 2000-11-16 Dennis Mason Method and apparatus for removing marine organisms from a submerged substrate
WO2015041538A1 (en) * 2013-09-17 2015-03-26 Jupa As Acid block and method of local acid treatment of subsea connecting element
GB2533749A (en) * 2013-09-17 2016-06-29 Jupa As Acid block and method of local acid treatment of subsea connecting element
NO340820B1 (en) * 2013-09-17 2017-06-26 Jupa As Acid block and method for local acid treatment of subsea connection element
US10041334B2 (en) 2013-09-17 2018-08-07 Jupa As Acid block and method of local acid treatment of subsea connecting element
GB2533749B (en) * 2013-09-17 2020-09-16 Jupa As Acid block and method of local acid treatment of subsea connecting element

Also Published As

Publication number Publication date
GB8605927D0 (en) 1986-04-16
GB2174105B (en) 1989-06-21

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PCNP Patent ceased through non-payment of renewal fee