NO345711B1 - Connection device for providing an electrical connection between a subsea pipeline and an electrical conductor - Google Patents
Connection device for providing an electrical connection between a subsea pipeline and an electrical conductor Download PDFInfo
- Publication number
- NO345711B1 NO345711B1 NO20181178A NO20181178A NO345711B1 NO 345711 B1 NO345711 B1 NO 345711B1 NO 20181178 A NO20181178 A NO 20181178A NO 20181178 A NO20181178 A NO 20181178A NO 345711 B1 NO345711 B1 NO 345711B1
- Authority
- NO
- Norway
- Prior art keywords
- connection
- pipeline
- plate
- rod
- electrical
- Prior art date
Links
- 239000004020 conductor Substances 0.000 title claims description 34
- 239000011248 coating agent Substances 0.000 description 7
- 238000000576 coating method Methods 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 238000003466 welding Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000005485 electric heating Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000013535 sea water Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 230000004323 axial length Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000005923 long-lasting effect Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000005067 remediation Methods 0.000 description 1
- 238000009420 retrofitting Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L53/00—Heating of pipes or pipe systems; Cooling of pipes or pipe systems
- F16L53/30—Heating of pipes or pipe systems
- F16L53/35—Ohmic-resistance heating
- F16L53/37—Ohmic-resistance heating the heating current flowing directly through the pipe to be heated
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
- H01R13/46—Bases; Cases
- H01R13/52—Dustproof, splashproof, drip-proof, waterproof, or flameproof cases
- H01R13/523—Dustproof, splashproof, drip-proof, waterproof, or flameproof cases for use under water
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2214/00—Aspects relating to resistive heating, induction heating and heating using microwaves, covered by groups H05B3/00, H05B6/00
- H05B2214/03—Heating of hydrocarbons
Description
FIELD OF THE INVENTION
The present invention relates to a connection device for providing an electrical connection between a subsea pipeline and an electrical conductor. In particular, the present invention relates to a connection device for providing an electrical connection between a subsea pipeline and an electrical conductor of a DEH system for the pipeline.
BACKGROUND OF THE INVENTION
A direct electrical heating (DEH) system is arranged for heating of subsea oil or gas pipelines in order to prevent hydrate and ice formation on the pipeline walls, and also for wax remediation. The pipe is heated by running alternating current (AC) through the steel in the pipe. By use of electrical current, the pipeline is heated to stay above critical temperature in the event of production shut down, low production rates or inadequate temperature in the pipeline. The DEH can be turned on when required.
In order to supply current to such a heating system the common practice is to install power supply cable that is connected to a supply cable as a so called "piggyback" cable. This piggyback cable is traditionally laid simultaneously with the laying of the pipeline. More specifically such a cable is strapped to the pipeline during installation thereof. The DEH piggyback cable conducts current from the platform end of the pipeline to the well (far end). At the well, the piggyback cable is connected to the pipeline and the current returns to the platform end trough the steel in the pipeline in parallel with the sea water. The piggyback cable is commonly placed as close to the thermally insulated pipeline as possible, as this yields optimum DEH system efficiency.
In some cases, it is necessary to install a retrofit DEH system onto an existing subsea oil or gas pipeline. The pipeline is typically coated to protect the pipeline against corrosion from seawater. In addition, the pipeline may be heat-insulated.
WO 2010/135772 shows retrofittable connectors mounted to the existing subsea pipeline at ROV-accessible locations. A clamp is connected to the pipeline. An electrical conductor is releasably fastened to the clamp by means of releasably screws or permanently mounted to the clamp using friction welding. In this publication, a relatively large section of coating must be removed from the pipeline before the clamp is mounted to the pipeline.
Document US 2010/0144181 A1 discloses a connector assembly for connecting and/or disconnecting an electric power cable to/from a subsea pipeline, in particular for direct electric heating thereof, comprising a female cone element mounted to the pipeline surface, a complementary male cone element attached to an end of the power cable, and bolt tightening means for securing contact between the female cone element and the male cone element.
One object of the invention is to reduce the area of the pipeline of which coating must be removed.
In general, it is cumbersome to provide an electrical connection between a subsea pipeline and electrical conductors. Typically, the available operation space around the pipeline is limited. Moreover, a large and robust connection surface area is often required between the subsea pipeline and the electrical conductors to avoid electrical arcs.
Hence, one object of the present invention is to provide a connection device for providing a reliable and long-lasting electrical connection between a subsea pipeline and an electrical conductor.
Another object of the invention is to provide a connection device for retrofitting a DEH system to a pipeline, where the above disadvantages are avoided.
Another object of the invention is to provide that the electrical connection can be performed by means of a ROV and ROV tools in an efficient operation.
SUMMARY OF THE INVENTION
The present invention relates to a connection device for providing an electrical connection between a subsea pipeline and an electrical conductor; characterized in that the connection device comprises:
- at least one connection rod having its first end configured to be friction welded to the subsea pipeline and its second end configured to protrude away from the subsea pipeline;
- a connection plate connected to the connection rod;
- a cable connector device electrically and mechanically connected to the connection plate.
As used herein, the term “protrude away from” means that after the friction welding process of the first end of the connection rod to the pipeline, there is a distance between the outer surface of the pipeline and the second end of the connection rod. Typically, the second end will protrude away in a substantially radial direction from the subsea pipeline. However, deviations from such a substantially radial direction is also possible.
The connection rods, the connection plate and the cable connector device are made of an electrically conducting material. The connection rods are mechanically and electrically connected to the subsea pipeline by means of the weld. The connection plate is electrically and mechanically connected to the connection rods. The cable connector device is electrically and mechanically connected to the connection plate. The cable connector device is configured to be electrically and mechanically connected to the electrical conductor. Hence, when connection rods of the connection device have been welded to the pipeline and cable connector device has been connected to the electrical conductor, electrical current may flow between the pipeline and the electrical conductor via the connection rods, the connection plate and the cable connector device.
In one aspect, the connection rod comprises a plate supporting element protruding in a direction away from a longitudinal axis of the connection rod. The plate supporting element may be connected to the connection rod by means of a weld, a threaded connection etc. Alternatively, the plate supporting element may be provided as part of the connection rod itself, i.e. the connection rod and the plate supporting element are manufactured as one single body.
In one aspect, the plate supporting element is connected to the connection rod.
In one aspect, the connection plate is connected between the plate supporting element of the connection rod and a connection element fixed to the second end of the connection rod.
In one aspect, the cable connector device comprises a clamp configured to be clamped around the electrical conductor.
In one aspect, the connection device comprises a number of connection rods configured to be friction welded to the subsea pipeline, and where the connection plate is provided as one common connection plate for the connection rods.
In one aspect, the connection device comprises a number of connection rods configured to be friction welded to the subsea pipeline, where there are one connection plate and one cable connector device for each connection rod. In such an embodiment, the connection plate and connector device may be formed by a cable shoe or cable eye.
DETAILED DESCRIPTION
Embodiments of the invention will be described in detail below with reference to the enclosed drawings, where:
Fig. 1 illustrates a simplified subsea pipeline;
Fig. 2 illustrates a DEH system retrofit onto the subsea pipeline of fig. 1;
Fig. 3 illustrates a cross sectional view of a first embodiment of the invention;
Fig. 4 illustrates a perspective view of the far end (location X1) of the subsea pipeline with its coating partially removed;
Fig. 5 illustrates a perspective view of the subsea pipeline with one connection rod welded to the subsea pipeline;
Fig. 6 illustrates a perspective view of the subsea pipeline with ten connection rods welded to the subsea pipeline;
Fig. 7a illustrates a cross sectional view of a first embodiment of the connection rod;
Fig. 7b illustrates a cross sectional view of a second embodiment of the connection rod;
Fig. 8 illustrates a perspective view of a connection plate member connected to the connection rods of fig. 6, the connection plate member having a inner cable connector;
Fig. 9 corresponds to fig.8, where the connection plate member has an outer cable connector;
Fig. 10 corresponds to fig. 9, where an electrical conductor has been connected to the cable connector of the connection plate member;
Fig. 11 illustrates a side view of the connection device at the near end (location X2) of the subsea pipeline with its coating partially removed;
Fig. 12 is a perspective view corresponding to fig. 11;
Fig. 13 illustrates a perspective view of an alternative electrical connection between the connection device and the electrical conductor;
Fig. 14 illustrates a top view of an alternative embodiment.
First, it is referred to fig. 1, where it is shown a subsea pipeline 1 connected to a topside structure 2. The subsea pipeline 1 is an oil and/or gas transferring pipeline. The topside structure 2 can be an onshore structure or an offshore structure, such as a platform, an FPSO or oil and/or gas receiving structures.
A first location X1 indicates the distal end of the pipeline 1 with respect to the structure 2. A second location X2 indicates a proximal location of the pipeline 1 with respect to the structure 2.
In fig. 2 it is shown that a direct electric heating (DEH) system 10 has been retrofitted on the pipeline 1 between the first and second locations X1 and X2. The DEH system 10 comprises a first DEH conductor 31 and a second DEH conductor 32. The DEH system 10 further comprises a power supply system 33 located at a third location X3, which in fig. 2 is shown located topside, but can be located subsea as well.
In fig. 2, it is shown that first ends 31a, 32a of the first and second DEH conductors 31, 32 are connected to a power supply system 33. It is also shown that a second end 31b of the first DEH conductor 31 is connected to the pipeline 1 at the first location X1, while the second end 32b of the second DEH conductor 32 is connected to the pipeline 1 at the second location X2;
In addition, the DEH system 10 comprises connection devices 40 which are used for connecting the second ends 31b, 32b of the first and second conductors 31, 32 to the pipeline 1. This will be described in detail below. It should be noted that it is possible to use one connection device 40 to connect one of the second ends 31b, 32b to the pipeline 1, while another type of connection method or connection device is used to connect the remaining one of the second ends 31b, 32b to the pipeline 1. In most practical solutions, the same connection device is used for both ends 31b, 32b.
In fig. 2 it is further shown a vessel 3 and a remotely operated vehicle (ROV) 4, which are performing the operation of connecting the first and second ends 31b, 32b to the pipeline by means of the ROV 4.
In addition, the DEH system 10 may comprise a so-called anode bank 50 with one or more anodes connected to one of or each of the connection devices 40, for example by means of a jumper cable, and positioned on the pipeline or on seabed close to the pipeline. The anode bank will be used to control the current density escaping out/in into the sea.
It is now referred to fig. 3, where a connection device 40 is shown. The connection device 40 comprises one or a number of connection rods 41, each having a first end 41a and a second end 41b. The first ends 41a of the respective connection rods 41 have been friction welded to the pipeline 1, while ensuring that they are protruding in a direction away from the subsea pipeline. Preferably, they are protruding in a radial direction with respect to a central axis II of the pipeline 1. In addition, the connection rods 41 shown in fig. 3 are preferably oriented parallel to each other.
The connection device 40 further comprises a connection plate 43 electrically and mechanically connected to the connection rods 41. In fig. 3, there are one common connection plate 43 for all connection rods 41.
The connection device 40 further comprises a cable connector device 45 electrically and mechanically connected to the connection plate 43. The cable connector device 45 is connectable to the electric conductor 31, and in fig. 3, the cable connector device 45 is electrically and mechanically connected to the electric conductor 31.
In fig. 7a and 7b, it is shown that the connection rod 41 comprises a plate supporting element 41c protruding in a direction away from a longitudinal axis I41 of the connection rod 41. The supporting element 41c is located at a distance DD away from the second end of the connection rod 41, thereby providing sufficient space to allow the second ends of the connection rods 41 to be inserted into openings provided through the connection plate 43.
In fig. 7a and 7b, it is also shown that the second end 41b of the connection rods 41 are threaded with outwardly facing threads for connection to a nut-type of connection element 43. Alternatively, the second end 41b of the connection rods 41 may be provided with an axial end opening with internal threads for connection to a bolt-type of connection element 42.
In fig. 3, it is shown that the connection device 40 further comprises a connection element 42 fixed to the respective second ends 41b of the connection rods 41. In the embodiment of fig. 3 and 7a and 7b, the connection element 42 is a nut for connection to the threaded second end 41b of the connection rods 41. Hence, the connection plate 43 is secured between the supporting element 41c and connection element 42. As mentioned above, the connection element 42 may also be a bolt or other type of connection element, depending on the chosen connection interface between the connection rods and connection elements.
The connection rods 41, the connection plate 43 and the cable connector device 45 are providing electrical contact between the pipeline 1 and the conductor 31 in order to provide that an electrical current may flow between the pipeline 1 and the electrical conductor 31 via the connection rods 41, the connection plate 43 and the cable connector device 45. Preferably, these parts 41, 43 and 45 are made of an electrically conducting material. Consequently, the connection rods 41 are mechanically and electrically connected to the subsea pipeline 1 by means of the friction weld, the connection plate 43 is electrically and mechanically connected to the connection rods 41 and the cable connector device 45 is electrically and mechanically connected to the connection plate 43.
It is now referred to fig. 4, where a subsea pipeline 1 is shown with an inner metallic pipe 1 and an outer coating 1b, where a section of the coating 1b is removed to access the metallic pipe 1. The coating area being removed is indicated as a section having an circumferential angle α of ca 45° and an axial length L of 0,5 – 1m. It should be noted that the method can be used on other pipelines 1 as well, for example uncoated pipelines.
Fig. 4 – 6 and 8 – 10 show the connection device used for connection of the second end 31b of the electrical conductor 31 to the pipeline 1 at the location X1.
In fig. 5, it is shown that one connection rod 41 has been friction welded to the metallic pipe 1. The friction welding process is performed by rotating the connection rod 41 in relation to the pipeline 1 and at the same time pushing the connection rod 41 towards the pipeline 1, thereby creating a friction weld. The friction welding process is considered known for a person skilled in the art and will not be described further in detail.
In fig. 6 it is shown that ten connection rods 41 have been friction welded to the pipeline. These connection rods 41 are distributed into two rows each having five rods 41. It should be noted that the connection rods 41 in the first row are substantially parallel with each other, and the connection rods 41 in the second row are substantially parallel with each other. It should be noted that there are many alternative embodiments of how the connection rods 41 are distributed, and the present invention is not limited to the distribution pattern of fig. 6.
In fig. 8, it is shown that the connection plate 43 is oriented correctly with respect to the connection rods 41, where the second ends 41b of the connection rods 41 have been inserted into openings 44 of the connection plate 43. It is also shown that a first clamp member 45a of the cable connector device 45 is secured to the connection plate 43.
It should be noted that the location and orientation of the connection bolts 41 during the friction welding process is predetermined with respect to the openings 44 of the connection plate. It should be noted that in one alternative embodiment, the connection plate 43 with its openings 44 may be used as a template for the location and orientation of the connection bolts 41 during the friction welding process.
In fig. 9, it is shown that the connection elements 42 has been connected to the second ends 41b of the connection rods 41. It is also shown that a second clamp member 45b of the cable connector device 45 is secured to the first clamp member 45a.
In fig. 10, it is shown that the second end 31b of the electrical conductor 31 has been connected between the first and second clamp members 45a, 45b of the cable connector device 45. ROV-operable bolts have been used to secure the second clamp member 45b to the first clamp member 45a.
Fig. 11 shows the corresponding connection device 40 used for connection of the second end 32b of the electrical conductor 32 to the pipeline 1 at the location X2.
In fig. 11 it is also shown that a clamp 60 has been connected to the pipeline 1. The purpose of the clamp 60 is to secure the electric conductor 31 mechanically in a desired position in relation to the pipeline 1 and in relation to the connection device 40 for the conductor 32.
It is now referred to fig. 7a and 7b again. In fig. 7a, the plate supporting element 41c is an element separate from the rod, which is connected to the connection rod 41. The element 41c can be a nut threaded onto the rod 41, it can be a metal element welded to the rod 41 etc.
In the alternative embodiment of fig. 7b, the plate supporting element 41c is provided as part of the connection rod 41 itself, i.e. the connection rod 41 and the plate supporting element 41c are manufactured as one single body.
It is now referred to fig. 13. Here, the cable connector device 45 comprises a clamp 46 clamped to the pipeline 1, where the conductor 31 is electrically connected to a connection interface 47 of the clamp 46. In addition, the cable connector device 45 comprises a bus bar 48 provided between the connection plate 43 and the clamp 46. It should be noted that a jumper cable or an extending section of the clamp 46 may be used as an alternative to the bus bar 48.
Yet an alternative embodiment is shown in fig. 14. Here, the connection device 40 comprises one connection plate 43 and one cable connector device 45 for each connection bolt 41. Here, the connection plate 45 and cable connector device 45 together form a cable shoe or cable eye.
Claims (7)
1. Connection device (40) for providing an electrical connection between a subsea pipeline (1) and an electrical conductor (31);
characterized in that the connection device (40) comprises:
- at least one connection rod (41) having its first end (41a) configured to be friction welded to the subsea pipeline (1) and its second end (41b) configured to protrude away from the subsea pipeline (1);
- a connection plate (43) connected to the connection rod (41);
- a cable connector device (45) electrically and mechanically connected to the connection plate (43).
2. Connection device (40) according to claim 1, where the connection rod (41) comprises a plate supporting element (41c) protruding in a direction away from a longitudinal axis (I41) of the connection rod (41).
3. Connection device (40) according to claim 2, where the plate supporting element (41c) is connected to the connection rod (41).
4. Connection device (40) according to claim 2 or 3, where the connection plate (43) is connected between the plate supporting element (41c) of the connection rod (41) and a connection element (42) fixed to the second end (41b) of the connection rod (41).
5. Connection device (40) according to any one of the above claims, where the cable connector device (45) comprises a clamp (45a, 45b) configured to be clamped around the electrical conductor (31).
6. Connection device (40) according to any one of the above claims, where the connection device (40) comprises a number of connection rods (41) configured to be friction welded to the subsea pipeline (1), and where the connection plate (43) is provided as one common connection plate (43) for the connection rods (41).
7. Connection device (40) according to any one of claims 1 -5, where the connection device (40) comprises one connection plate (43) and one cable connector device (45) for each connection rod (41).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NO20181178A NO345711B1 (en) | 2018-09-11 | 2018-09-11 | Connection device for providing an electrical connection between a subsea pipeline and an electrical conductor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NO20181178A NO345711B1 (en) | 2018-09-11 | 2018-09-11 | Connection device for providing an electrical connection between a subsea pipeline and an electrical conductor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| NO20181178A1 NO20181178A1 (en) | 2020-03-12 |
| NO345711B1 true NO345711B1 (en) | 2021-06-28 |
Family
ID=70802973
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NO20181178A NO345711B1 (en) | 2018-09-11 | 2018-09-11 | Connection device for providing an electrical connection between a subsea pipeline and an electrical conductor |
Country Status (1)
| Country | Link |
|---|---|
| NO (1) | NO345711B1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004102059A1 (en) * | 2003-05-01 | 2004-11-25 | Shell Internationale Research Maatschappij B.V. | Mid-line connector and method for pipe-in-pipe electrical heating. |
| US20100144181A1 (en) * | 2006-12-14 | 2010-06-10 | Jan Erik Karlsen | Connector assembly |
| WO2010135772A1 (en) * | 2009-05-25 | 2010-12-02 | Woodside Energy Limited | Direct electric heating of subsea piping installations |
-
2018
- 2018-09-11 NO NO20181178A patent/NO345711B1/en unknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004102059A1 (en) * | 2003-05-01 | 2004-11-25 | Shell Internationale Research Maatschappij B.V. | Mid-line connector and method for pipe-in-pipe electrical heating. |
| US20100144181A1 (en) * | 2006-12-14 | 2010-06-10 | Jan Erik Karlsen | Connector assembly |
| WO2010135772A1 (en) * | 2009-05-25 | 2010-12-02 | Woodside Energy Limited | Direct electric heating of subsea piping installations |
Also Published As
| Publication number | Publication date |
|---|---|
| NO20181178A1 (en) | 2020-03-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10180200B2 (en) | Method of installing an electrically-heatable subsea flowline and electrically-heatable subsea flowline thereof | |
| US8388363B2 (en) | Connector assembly | |
| US20120125906A1 (en) | Thermally isolated heated pipeline made of double casing sections and laying process for such a pipeline | |
| WO2010135772A1 (en) | Direct electric heating of subsea piping installations | |
| US10985544B2 (en) | Subsea connector with u-shaped configuration | |
| EP2504517A2 (en) | Riser configuration | |
| EP2703702B1 (en) | Piggy back holdback clamp | |
| US11170915B2 (en) | Subsea cable system and a method for supplying electrical power to a subsea device | |
| US6328583B2 (en) | Re-connectable pipeline connection for direct heating system | |
| NO345711B1 (en) | Connection device for providing an electrical connection between a subsea pipeline and an electrical conductor | |
| US10897094B2 (en) | Clamping device and method for providing an electrical connection between a subsea pipeline and an electrical conductor | |
| US20120305543A1 (en) | Heating of pipe sections | |
| CA3027043C (en) | Clamping assembly for attaching a grounding conductor to a pipe having a protective coating | |
| JP2008245340A (en) | Cable protective tube, and submarine cable laying method using the same | |
| KR20130014108A (en) | Apparatus for installation of power cable | |
| US20200080677A1 (en) | Tapping sleeve with bent ends | |
| EP3942213A1 (en) | Subsea pipelines equipped with direct electrical heating systems | |
| TW202324867A (en) | Submarine cable system and method for laying a submarine cable system | |
| WO2014032704A1 (en) | Method and apparatus for connecting pipes together | |
| KR20170033053A (en) | Riser pipe valve structure and offshore structure having the same | |
| NO343094B1 (en) | Installing Heated Subsea Pipelines |