CA2522559A1 - Pipeline cathodic protection connection - Google Patents
Pipeline cathodic protection connection Download PDFInfo
- Publication number
- CA2522559A1 CA2522559A1 CA002522559A CA2522559A CA2522559A1 CA 2522559 A1 CA2522559 A1 CA 2522559A1 CA 002522559 A CA002522559 A CA 002522559A CA 2522559 A CA2522559 A CA 2522559A CA 2522559 A1 CA2522559 A1 CA 2522559A1
- Authority
- CA
- Canada
- Prior art keywords
- pipe
- sleeve
- connection
- electrical
- electrical connection
- 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.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
- C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
- C23F13/20—Conducting electric current to electrodes
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
- C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
- C23F13/18—Means for supporting electrodes
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F2213/00—Aspects of inhibiting corrosion of metals by anodic or cathodic protection
- C23F2213/30—Anodic or cathodic protection specially adapted for a specific object
- C23F2213/32—Pipes
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Prevention Of Electric Corrosion (AREA)
Abstract
A pipeline cathodic protection connection is provided to create a mechanical electrical connection on an operating pipe in conjunction with an external pipe reinforcing sleeve arrangement. The outer surface of the pipe and the inner surface of the pipe reinforcing sleeve are cleaned, and an epoxy filler material is applied to the pipe over the area to be covered by the external pipe reinforcing sleeve. A mechanical connecting apparatus is provided on the external surface of the pipe reinforcing sleeve to connect the sleeve to cathodic protection equipment. The sleeve is then installed around the pipe to mechanically electrically connect the sleeve to the pipe. The epoxy acts both as a filler agent and sealant, preventing the external environment from interfering with the mechanical electrical connection. The pipe sleeve therefore acts as one unit, expanding and contracting with fluctuations in the pipe's pressure and temperature while maintaining the mechanical electrical connection to the pipe.
Description
TEM File No. 145.6 TITLE: PIPELINE CATHODIC PROTECTION CONNECTION
s FIELD OF THE INVENTION
The present invention relates to a method and device to make an electrical connection to a pipe, and in particular to an electrical connection to pipes used in the oil and gas industry.
to BACKGROUND OF THE INVENTION
It is well known that pipes in general, and particularly buried pipes used in the oil and gas industry, are subject to corrosion caused by the electrical potential difference between the metallic surface of the pipe and the adjacent soil. During installation and operation of a pipeline, electric wires are attached to is the exterior surface of the pipe. The wire connection is then attached to a cathodic protection system that sets the voltage potential of the pipe as a cathode and the soil as an anode. In areas where AC mitigation is required, the electrical connection must be capable of transmitting large amperages.
The usual method of attaching the wire to the pipe is using a thermite 2o welding process. A disadvantage of this prior method is that it creates potentially severe unknown stresses in the pipe wall. In one instance, the use of the thermite process on an operating pipeline caused a blowout on the pipe that resulted in a fire. Another disadvantage of the current art is that it can be unsuitable to carry large amperage flows where AC mitigation is required.
2s What is desired therefore is an installation device and process that overcomes the limitations and disadvantages of the prior art. Preferably the cathodic protection connection of the present invention should not require thermite welding to the pipe, and should be capable of being installed whether the pipe is pressurized (i.e. operating) or not. If installed while the pipe is pressurized, the cathodic protection connection should maintain a working electrical connection to the pipe upon depressurization or shut down. Also, the cathodic protection connection should be capable of transferring large s amperages (in the order of 800 amperes). Further, the method of installing the cathodic protection connection should be relatively quick and efficient to reduce installation costs and should continue to provide a working electrical connection to the pipe over time.
to SUMMARY OF THE INVENTION
The present invention provides a method of forming an electrical connection to a pipe as follows:
providing an installation apparatus having a means for electrical connection to the pipe;
Is installing the installation apparatus on the pipe;
installing an external pipe reinforcing sleeve over the pipe; and, connecting an electrical wire to the external pipe reinforcing sleeve .
In another aspect the invention provides a method of providing cathodic protection to a pipe comprising:
2o providing an installation apparatus having a means for connection to an electrical source;
installing the installation apparatus onto the pipe; and, verifying that electrical connection exists.
In yet another aspect the invention provides a cathodic connection 2s protection apparatus for a pipe comprising:
first and second sleeve segments for mounting onto said pipe;
connector plates for joining said sleeve segments about said pipe;
s FIELD OF THE INVENTION
The present invention relates to a method and device to make an electrical connection to a pipe, and in particular to an electrical connection to pipes used in the oil and gas industry.
to BACKGROUND OF THE INVENTION
It is well known that pipes in general, and particularly buried pipes used in the oil and gas industry, are subject to corrosion caused by the electrical potential difference between the metallic surface of the pipe and the adjacent soil. During installation and operation of a pipeline, electric wires are attached to is the exterior surface of the pipe. The wire connection is then attached to a cathodic protection system that sets the voltage potential of the pipe as a cathode and the soil as an anode. In areas where AC mitigation is required, the electrical connection must be capable of transmitting large amperages.
The usual method of attaching the wire to the pipe is using a thermite 2o welding process. A disadvantage of this prior method is that it creates potentially severe unknown stresses in the pipe wall. In one instance, the use of the thermite process on an operating pipeline caused a blowout on the pipe that resulted in a fire. Another disadvantage of the current art is that it can be unsuitable to carry large amperage flows where AC mitigation is required.
2s What is desired therefore is an installation device and process that overcomes the limitations and disadvantages of the prior art. Preferably the cathodic protection connection of the present invention should not require thermite welding to the pipe, and should be capable of being installed whether the pipe is pressurized (i.e. operating) or not. If installed while the pipe is pressurized, the cathodic protection connection should maintain a working electrical connection to the pipe upon depressurization or shut down. Also, the cathodic protection connection should be capable of transferring large s amperages (in the order of 800 amperes). Further, the method of installing the cathodic protection connection should be relatively quick and efficient to reduce installation costs and should continue to provide a working electrical connection to the pipe over time.
to SUMMARY OF THE INVENTION
The present invention provides a method of forming an electrical connection to a pipe as follows:
providing an installation apparatus having a means for electrical connection to the pipe;
Is installing the installation apparatus on the pipe;
installing an external pipe reinforcing sleeve over the pipe; and, connecting an electrical wire to the external pipe reinforcing sleeve .
In another aspect the invention provides a method of providing cathodic protection to a pipe comprising:
2o providing an installation apparatus having a means for connection to an electrical source;
installing the installation apparatus onto the pipe; and, verifying that electrical connection exists.
In yet another aspect the invention provides a cathodic connection 2s protection apparatus for a pipe comprising:
first and second sleeve segments for mounting onto said pipe;
connector plates for joining said sleeve segments about said pipe;
a connection member attached to one of said sleeve segments, and adapted for electrical communication with said sleeve segment and a power source;
wherein said sleeve segments are in electrical contact with said pipe to provided electrical communication between said pipe and power source.
s DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:
Figure 1 is a perspective view of a pipe showing an external pipe reinforcement to sleeve being mounted over the pipe, with a cathodic protection electrical connection attached to the top; and, Figure 2 is a cross-sectional view of fig.1 after the cathodic protection connection is installed on the pipe.
Is DESCRIPTION OF PREFERRED EMBODIMENTS
The figures show an installation apparatus (generally indicated by reference numeral 2) and method according to a preferred embodiment of the invention for installing an electrical cathodic protection connection 4 onto a pipe 1. The installation apparatus 2 is mounted onto the outer surface 1 a of a 20 longitudinal section of the pipe. For illustrative purposes, the pipe 1 is one which transports hydrocarbons under pressure, such as a natural gas or oil pipeline.
Whether the pipeline is located above or below ground, it is typically subject to internal pressure fluctuations, internal and external temperature fluctuations, and to both internal and external corrosive agents. It will be appreciated by those 2s skilled in the art, however, that the installation apparatus 2 is not restricted to use on such pipelines but is also suitable for use on various types of pipes, such as those used for transporting drinking water, sewage, and a host of other liquids and gases, whether pressurized or not.
wherein said sleeve segments are in electrical contact with said pipe to provided electrical communication between said pipe and power source.
s DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:
Figure 1 is a perspective view of a pipe showing an external pipe reinforcement to sleeve being mounted over the pipe, with a cathodic protection electrical connection attached to the top; and, Figure 2 is a cross-sectional view of fig.1 after the cathodic protection connection is installed on the pipe.
Is DESCRIPTION OF PREFERRED EMBODIMENTS
The figures show an installation apparatus (generally indicated by reference numeral 2) and method according to a preferred embodiment of the invention for installing an electrical cathodic protection connection 4 onto a pipe 1. The installation apparatus 2 is mounted onto the outer surface 1 a of a 20 longitudinal section of the pipe. For illustrative purposes, the pipe 1 is one which transports hydrocarbons under pressure, such as a natural gas or oil pipeline.
Whether the pipeline is located above or below ground, it is typically subject to internal pressure fluctuations, internal and external temperature fluctuations, and to both internal and external corrosive agents. It will be appreciated by those 2s skilled in the art, however, that the installation apparatus 2 is not restricted to use on such pipelines but is also suitable for use on various types of pipes, such as those used for transporting drinking water, sewage, and a host of other liquids and gases, whether pressurized or not.
A large pipe surface area extending in a band about the circumference of the pipe is made ready for mounting the installation apparatus 2, which is preferably an external pipe reinforcing sleeve according to applicant's Canadian patent 2,164,011 and US patent 5,722,463 (incorporated herein by reference) s with some modification. A threaded metal lug 4 is attached to the top half of the sleeve (such as by welding or like means) to provide a means of connection to an electrical conduit, such as wire 6, for communication with an external electrical source. For relatively small bolted connections, the lug 4 may be as simple as a typical nut, and for larger connections a custom threaded member to may be made. Although a threaded lug is preferred for ease of connection to the wire 6 (which can have a male threaded end), it will be appreciated that the lug may take other forms as well (whether threaded or not), so long as a suitable electrical connection may be achieved with the wire and/or ultimately with the electrical source.
is A layer of binding agent 3, such as an epoxy material, should cover substantially the entire band. The inside surfaces 2a of both sleeve segments of the installation apparatus 2 are also cleaned, and are installed over the binding agent 3. The sleeve segments should be clamped, and connector plates 7 are then welded to the opposed ends of the sleeve segments to complete the 2o installation. The connector plates may be pre-attached to a sleeve segment, as seen in fig.1. A lead strip 5 is optionally placed between the pipe 1 and the sleeve 2, preferably beneath the connection 4 to form the shortest electrical path with the pipe. Placing the strip at the pipe's apex also helps it remain on the pipe during installation. Although more than one lead strip may be placed at any 2s location about the pipe, this is not preferred. When a lead strip is used, the binding agent 3 is not placed over (or under) the lead strip 5 to avoid interference of the electrical connection with the pipe and sleeve. The electrical wire 6 can then be attached to the threaded lug 4, and a verification procedure may be done to confirm that the desired electrical connection exists.
Good results have been achieved both with and without the presence of the lead strip 5 in tests up to 800 amps. If sufficient clamping force is applied to s the sleeves during installation to bring portions of the sleeves into contact with the pipe (thus squeezing away the epoxy in those locations), then the desired electrical conductivity between the sleeves and pipe is realized without the strip(s).
Several advantages and benefits of the present invention may now be to better appreciated. First, it avoids the drawback of many prior art pipe protection methods that require thermite welding or the applying of metal strapping around the pipe. In the prior art methods the use of a thermite weld causes an arc burn to the pipe, a condition not accepted within the pipeline industry. Second, in the present invention the cathodic protection electrical connection is held in place by is the epoxy 3, thus providing a permanent assembly. Thirdly, the epoxy 3 provides a seal, preventing any subsurface water from entering between the sleeve 2 and the pipe 1 which could cause corrosion and poor electrical contact between the pipe 1 and the sleeve 2. Fourth, by having lug 4 attached to the sleeve, the possibility of the electrical wire 6 being broken from the assembly is greatly 2o minimized. Fifth, the present invention provides the ability to attach an electrical connection to a pipe irrespective of the pipe wall thickness and internal pressure.
Sixth, the pipe, and sleeve have been found to act as one unit during pressurizing and depressurizing of the pipe, namely without any dislocation of the contact between the sleeve and the pipe.
2s The above description is intended in an illustrative rather than a restrictive sense and variations to the specific configurations described may be apparent to skilled persons in adapting the present invention to specific applications.
Such variations are intended to form part of the present invention insofar as they are within the spirit and scope of the claims below.
is A layer of binding agent 3, such as an epoxy material, should cover substantially the entire band. The inside surfaces 2a of both sleeve segments of the installation apparatus 2 are also cleaned, and are installed over the binding agent 3. The sleeve segments should be clamped, and connector plates 7 are then welded to the opposed ends of the sleeve segments to complete the 2o installation. The connector plates may be pre-attached to a sleeve segment, as seen in fig.1. A lead strip 5 is optionally placed between the pipe 1 and the sleeve 2, preferably beneath the connection 4 to form the shortest electrical path with the pipe. Placing the strip at the pipe's apex also helps it remain on the pipe during installation. Although more than one lead strip may be placed at any 2s location about the pipe, this is not preferred. When a lead strip is used, the binding agent 3 is not placed over (or under) the lead strip 5 to avoid interference of the electrical connection with the pipe and sleeve. The electrical wire 6 can then be attached to the threaded lug 4, and a verification procedure may be done to confirm that the desired electrical connection exists.
Good results have been achieved both with and without the presence of the lead strip 5 in tests up to 800 amps. If sufficient clamping force is applied to s the sleeves during installation to bring portions of the sleeves into contact with the pipe (thus squeezing away the epoxy in those locations), then the desired electrical conductivity between the sleeves and pipe is realized without the strip(s).
Several advantages and benefits of the present invention may now be to better appreciated. First, it avoids the drawback of many prior art pipe protection methods that require thermite welding or the applying of metal strapping around the pipe. In the prior art methods the use of a thermite weld causes an arc burn to the pipe, a condition not accepted within the pipeline industry. Second, in the present invention the cathodic protection electrical connection is held in place by is the epoxy 3, thus providing a permanent assembly. Thirdly, the epoxy 3 provides a seal, preventing any subsurface water from entering between the sleeve 2 and the pipe 1 which could cause corrosion and poor electrical contact between the pipe 1 and the sleeve 2. Fourth, by having lug 4 attached to the sleeve, the possibility of the electrical wire 6 being broken from the assembly is greatly 2o minimized. Fifth, the present invention provides the ability to attach an electrical connection to a pipe irrespective of the pipe wall thickness and internal pressure.
Sixth, the pipe, and sleeve have been found to act as one unit during pressurizing and depressurizing of the pipe, namely without any dislocation of the contact between the sleeve and the pipe.
2s The above description is intended in an illustrative rather than a restrictive sense and variations to the specific configurations described may be apparent to skilled persons in adapting the present invention to specific applications.
Such variations are intended to form part of the present invention insofar as they are within the spirit and scope of the claims below.
Claims (8)
1. A method of providing cathodic protection to a pipe comprising:
providing an installation apparatus having a means for connection to an electrical source;
installing the installation apparatus onto the pipe; and, verifying that electrical connection exists.
providing an installation apparatus having a means for connection to an electrical source;
installing the installation apparatus onto the pipe; and, verifying that electrical connection exists.
2. The method of claim 1 further comprising installing an external pipe reinforcing sleeve assembly to mechanically complete an electrical connection to the pipe.
3. The method of claim 2 comprising placing an epoxy material between the pipe and sleeve to provide a seal therebetween.
4. The method of claim 2 wherein said means for connecting comprises a metal lug mounted to said sleeve to form a point of electrical connection thereto.
5. A cathodic connection protection apparatus for a pipe comprising:
first and second sleeve segments for mounting onto said pipe;
connector plates for joining said sleeve segments about said pipe;
a connection member attached to one of said sleeve segments, and adapted for electrical communication with said sleeve segment and a power source;
wherein said sleeve segments are in electrical contact with said pipe to provided electrical communication between said pipe and power source.
first and second sleeve segments for mounting onto said pipe;
connector plates for joining said sleeve segments about said pipe;
a connection member attached to one of said sleeve segments, and adapted for electrical communication with said sleeve segment and a power source;
wherein said sleeve segments are in electrical contact with said pipe to provided electrical communication between said pipe and power source.
6. The apparatus of claim 5 further comprising an epoxy material placed between the sleeve segments and the pipe.
7. The apparatus of claims 5 or 6 further comprising a lead strip placed between at least one of the sleeve segments and the pipe.
8. The apparatus of claim 7 wherein said lead strip is placed intermediate the connection member and the pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002522559A CA2522559A1 (en) | 2005-10-07 | 2005-10-07 | Pipeline cathodic protection connection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002522559A CA2522559A1 (en) | 2005-10-07 | 2005-10-07 | Pipeline cathodic protection connection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2522559A1 true CA2522559A1 (en) | 2007-04-07 |
Family
ID=37912334
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002522559A Abandoned CA2522559A1 (en) | 2005-10-07 | 2005-10-07 | Pipeline cathodic protection connection |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2522559A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107313721A (en) * | 2017-05-04 | 2017-11-03 | 中石油煤层气有限责任公司 | Pumpingh well impressed current method anti-corrosive apparatus |
-
2005
- 2005-10-07 CA CA002522559A patent/CA2522559A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107313721A (en) * | 2017-05-04 | 2017-11-03 | 中石油煤层气有限责任公司 | Pumpingh well impressed current method anti-corrosive apparatus |
| CN107313721B (en) * | 2017-05-04 | 2024-02-20 | 中石油煤层气有限责任公司 | External current method anticorrosion device for pumping well |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |
Effective date: 20130516 |
|
| FZDE | Discontinued |
Effective date: 20130516 |