NO20151765A1 - Subsea system - Google Patents

Subsea system Download PDF

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Publication number
NO20151765A1
NO20151765A1 NO20151765A NO20151765A NO20151765A1 NO 20151765 A1 NO20151765 A1 NO 20151765A1 NO 20151765 A NO20151765 A NO 20151765A NO 20151765 A NO20151765 A NO 20151765A NO 20151765 A1 NO20151765 A1 NO 20151765A1
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NO
Norway
Prior art keywords
communication
lines
subsea
bus
power
Prior art date
Application number
NO20151765A
Inventor
Per Helgerud
Eivind Sjøtun Helganger
Thomas André Karlberg
Egil Mulstad Skrivervik
Vidar Nicolaysen
Original Assignee
Fmc Kongsberg Subsea As
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
Application filed by Fmc Kongsberg Subsea As filed Critical Fmc Kongsberg Subsea As
Priority to NO20151765A priority Critical patent/NO20151765A1/en
Publication of NO20151765A1 publication Critical patent/NO20151765A1/en

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/54—Systems for transmission via power distribution lines
    • H04B3/542—Systems for transmission via power distribution lines the information being in digital form
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B47/00—Survey of boreholes or wells
    • E21B47/12—Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/40—Bus networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2203/00—Indexing scheme relating to line transmission systems
    • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
    • H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
    • H04B2203/5416—Methods of transmitting or receiving signals via power distribution lines by adding signals to the wave form of the power source
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2203/00—Indexing scheme relating to line transmission systems
    • H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
    • H04B2203/5462—Systems for power line communications
    • H04B2203/5475—Systems for power line communications adapted for drill or well combined with data transmission
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/40—Bus networks
    • H04L2012/40208—Bus networks characterized by the use of a particular bus standard
    • H04L2012/40215—Controller Area Network CAN

Description

FIELD OF THE INVENTION
The present invention relates to a subsea system with subsea modules communicating with each other by means of power line communication.
BACKGROUND OF THE INVENTION
There are several standards for communication between electric units in industrial systems. One such standard digital communication protocol is the CAN bus, more specifically the Fault Tolerant CAN bus. The CAN standard has the advantage of being a bus type communication, but has a very limited band width.
Another standard is the 10/lOOBASE-T Ethernet. Ethernet has high bandwidth and supports IP communication, but is only point-to-point and requires a high number of wires with specific physical line parameters, as defined in its standard IEEE 802.3.
Accordingly, these two standards offer a choice between low speed bus communication, and high speed point-to-point communication with IP traffic support.
Ethernet is becoming industry standard through the joint industry program Subsea Instrumentation Interface Standardization (SUS), together with 24 VDC power supply and CAN bus.
In subsea systems, communication lines must be provided through pressure barriers, causing a need for so-called penetrations in the pressure barriers. Each such penetration increases the risk of a failing pressure barrier and it also contributes to the costs of the subsea system. Hence, one object of the invention is to reduce the number of wires, number of connection points and hence the number of penetrations in subsea systems.
As some electric units are already equipped with CAN bus communication equipment, one object of the invention is to utilize the CAN bus lines while at the same time avoid some of the disadvantages of the CAN bus.
A challenge with subsea cables is that they degrade over time, which again may cause more errors in communication over older cables. One object of the invention is to improve the robustness of subsea communication even with older cables.
SUMMARY OF THE INVENTION
The present invention relates to a subsea system comprising:
- first and second lines; - a first subsea module comprising a first electric unit; - a second subsea module comprising a second electric unit;
where the first subsea module further comprises a first communication unit connected to the first electric unit;
where the second subsea module comprises a second communication unit connected to the second electric unit;
where the first and second communication units are connected to the first and second lines;
where the first and second communication units are configured to communicate with each other by means of power line communication.
There are several types of such power line communication. One standard for providing communication via power lines is the IEEE 1901 standard, often referred to as the HomePlug standard. Hence, in one aspect of the invention, the first and second communication units are configured to communicate with each other by means of the IEEE 1901 standard.
The first and second lines may be signal lines, for example the lines or conductors of a coaxial cable. Alternatively, the first and second lines may be power lines, such as 230 VAC lines, 24 VDC lines or other types of power line wires. It should be noted that the IEEE 1901 standard may also be used for communication via other communication lines than power lines, such as for example the above coaxial cable.
In one aspect, the first subsea module further comprises a first bus communication unit connected to the first electric unit; and the second subsea module further comprises a second bus communication unit connected to the second electric unit, where the first and second bus communication units are connected to bus communication lines of a communication bus.
In one aspect, the first and second bus communication units are CAN bus communication units connected to CAN bus communication lines of a CAN communication bus. In such a case, the first and second lines can be the CAN power lines. Alternatively, the first and second lines can be lines separate from the CAN power lines.
In one aspect, if the first and second lines are power lines, the first and/or second electric unit may be connected to these first and second power lines for receiving electrical power via the first and second power lines.
In one aspect, the first communication unit and the first bus communication unit are configured to provide redundant or complementary communication with the second communication unit and the second bus communication unit.
In one aspect, if the first and second lines are communication lines, the at least one of the first and/or second electric unit may be connected to auxiliary power lines and/or a battery for receiving electrical power via the respective auxiliary power lines and/or battery.
The first and second electric units may be a sensor device, an actuator device, a battery device, a computer device, an AUV and/or control device.
The system may further comprises a third line, where the first and second communication units are connected to the third line and where the first and second communication units are configured to communicate with each other by means of the power line communication, for example the IEEE 1901 standard, via the first, second and third lines.
DETAILED DESCRIPTION
Embodiments of the invention will now be described with reference to the enclosed drawings, where: Fig. 1 illustrates a first embodiment of the invention; Fig. 2 illustrates a second embodiment of the invention in which a CAN bus is used;
Fig. 3 illustrates a subsea system utilizing the invention
Fig. 4 illustrates a third embodiment of the invention; Fig. 5 illustrates a fourth embodiment of the invention; Fig. 6 illustrates yet an alternative embodiment of the invention; Fig. 7 illustrates yet an alternative embodiment of the invention; Fig. 8 illustrates yet an alternative embodiment of the invention;
Fig. 9 illustrates yet an alternative embodiment of the invention.
It is now referred to fig. 1. Here a subsea system is generally referred to with reference number 1. The subsea system 1 comprises a first subsea module 10 comprising a first electric unit 10a and a second subsea module 11 comprising a second electric unit lia.
The electric circuit 10a of the first module 10 may for example be a sensor device for sensing fluid pressure in a fluid line of a subsea Christmas tree, while the electric circuit 1 lb of the second module 11 may be a control system for controlling the subsea Christmas three. Such a subsea system 1 may of course comprise several such additional modules, for example a third module håving a third electric circuit for actuating a valve in the subsea Christmas tree. More examples of such modules will be described below with reference to fig. 3.
The first subsea module 10 further comprises a first communication unit 10b connected to the first electric unit 10a by means of a first communication line 30a. The second subsea module 11 comprises a second communication unit 11b connected to the second electric unit 1 la by means of a second communication line 31a.
The subsea system 1 further comprises first and second lines 21, 22, where the first and second communication units 10b, 11b are connected to the first and second lines 21, 22. A line is here a conductor. Hence, one cable may comprise several lines or conductors.
Accordingly, by using the above example, the fluid pressure sensed by the first electric circuit 10a may be communicated to the second electric circuit 11, which may control the third electric circuit to actuate a valve.
In the present invention, the first and second communication units 10b, 11b are configured to communicate with each other by means of the IEEE 1901 communication standard via the first and second lines 21, 22. This standard is often referred to as the HomePlug communication standard, and is used today for communication in land based systems, more specifically for hornes and so called smart hornes (automated reading of electricity meters, power consumption management, smart home appliance, etc).
The HomePlug Alliance (http://www.homeplug.org) is a certifying body for IEEE 1901 products. One of the sub-specifications of this standard, the Homeplug Green PHY™ has the additional advantage of being more robust and has a lower power consumption, which makes it suitable for subsea applications.
Integrated Circuits for communication by means of IEEE 1901 are commercially available, hence, this standard will not be described herein.
Below, further examples of subsea systems will be described in detail.
Example 1
It is now referred to fig. 1 again. Here the first and second lines 21, 22 are electric power lines, such as 24V DC lines, 23 OV AC lines etc. It should be noted that the invention is not limited to such power levels - the IEEE 1901 standard may be used for communication on a variety of different power lines.
In fig. 1, the first and second electric units 10a, 10b are connected to the first and second power lines 21, 22 for receiving electrical power via the first and second power lines 21, 22. Hence, the first and second lines 21 and 22 here have a dual purpose as they are used both as power supply lines and as communication lines. This dual purpose is considered to be a part of the IEEE 1901 standard itself.
Example 2
It is now referred to fig. 2. Here, the first subsea module 10 further comprises a first CAN communication unit 10c connected to the first electric unit 10a via communication line 30b and the second subsea module 11 further comprises a second CAN communication unit lic connected to the second electric unit lia via communication line 31b.
The term CAN is here referring to the CAN (controller area network) bus communication standard defined in the ISO 11898 standard. This standard is a commonly used communication standard in industrial applications and will not be described further herein.
The first and second CAN communication units 10c, lic are connected to CAN communication lines 23, 24 of a CAN bus. These communication lines 23, 24 of the CAN-bus are often referred to as CANH and CANL. In addition, the CAN bus comprises to power lines shown in fig. 2 as lines 21, 22, which often are referred to as power lines GND, VDC.
Here, the first and second commination units 10b, 11b are connected to the power lines 21, 22 (or GND, VDC) of the CAN bus. Accordingly, also in this example the lines 21, 22 are considered to be electric power lines.
Hence, modules 10, 11 may communicate with each other through CAN communication via the first and second CAN communication units 10c, lic. In addition, the modules 10,11 may communicate with each other through HomePlug communication via the first and second communication units 10b, 11b. In this way, it is possible to provide redundant communication, i.e. the same type of information is communicated in two different channels. Alternatively, it is possible to provide complementary communication, i.e. one type of information is communicated via CAN and a second type of information is communicated via HomePlug.
As shown in fig. 2, the electric circuits 10a, 10b are supplied with electric power from the CAN power lines 21, 22.
As shown in fig. 2, the electric circuits 10a, 10b are supplied with electric power from the CAN power lines 21, 22.
During normal operation, CAN communication will not be interrupted by HomePlug communication on lines 21, 22 and HomePlug communication will not be interrupted by CAN communication. This also applies to fault tolerant CAN communication (FT-CAN). Hence, in the embodiment in fig. 2, both FT-CAN and HomePlug communication is working within their respective standards, no exceptions from their standards are needed. This also applies if the FT-CAN nodes are operating in any supported failure mode(s), both FT-CAN and HomePlug can coexist.
Example 3
It is now referred to fig. 3. Here it is shown a subsea system 1 comprising five modules 10, 11, 12, 13 and 14, each håving an electric circuit 10a, lia, 12a, 13a and 14a and each håving communication unit 10b, 11b, 12b, 13b and 14b. The communication units 10b, 11b, 12b, 13b and 14b are communicating by means of the HomePlug communication standard as described in the above examples.
It is shown that the first electric circuit 10a is a control system, the second electric circuit lia is a sensor, the third electric circuit 12a is an actuator, the circuit 13a is an other device, such as a battery device, a computer device, AUV (Autonomous Underwater Vehicle etc. The control system 10a may for example perform computations of control signals to the actuator 12a based on signals received from the sensor 1 la in addition to signals received via a line 40 and/or signals received from the sub system control 14a.
The fifth electric circuit 14a is here shown as a sub system control for controlling a subsystem connected to the fifth module 14 via a line 41. The lines 40, 41 may also be lines for communication by means of the HomePlug communication standard, or they may be optic communication lines, CAN communication lines etc.
Example 4
It is now referred to fig. 4. Here, two modules 10, 11 are shown as in fig. 1. However, the first and second lines 21, 22 are here communication lines, not power lines as in fig. 1. The first and second lines 21, 22 may here be for example a coaxial cable, or they may be copper wires etc. It should be noted that the first and second lines 21, 22 may be suitable for transferring power and signals, but they are not used for transferring power.
Hence, auxiliary power supplies are used to supply power to the electric circuits 10a, 10b of the modules 10, 11. In fig. 4 auxiliary power lines 25, 26 are shown, where the first electric circuit 1 Oa of the first module 10 is connected to the auxiliary lines 25, 26. The second electric circuit lia is connected to a battery 27 provided in the module 11.
Alternatively, the battery 27 could be provided outside of the module 27, for example there could be one common battery for both modules 10, 11. In yet an alternative, the auxiliary power lines 25, 26 could be connected to the battery 27 to provide UPS functionality, i.e. that the electric circuit lia is supplied with power from auxiliary power lines 25, 26, but if there is a failure in that power supply, the battery will be able to supply power to the circuit 1 la for a limited period of time. When the failure is corrected, the battery will be recharged from the auxiliary power lines 25, 26.
Example 5
It is now referred to fig. 5. Here, the first module 10 has a first communication unit 10b for HomePlug communication via first and second power lines 21, 22. The first module also has a first CAN communication unit 10c for communication on a CAN bus as described in the second example above. Here, the power lines 25, 26 of the CAN bus itself are not used for communication. Alternatively, the power lines 25, 26 may be used for FT-CAN in its failure mode(s).
The second module 11 has a first communication unit 1 lb for HomePlug communication via first and second power lines 21, 22. The second module 11 does not have a CAN communication unit.
The third module 12 has a third CAN communication unit 12c for communication on a CAN bus as described in the second example above. The third module 12 does not have a HomePlug communication unit.
Accordingly, the first module 10 may communicate with the second and third modules 11, 12, while the second and third modules 11, 12 may not communicate directly with each other.
In fig. 5, all electric circuits 10a, lia, 12a are supplied with power from the first and second power lines 21, 22.
This example may be used in cases where the electronic units 10a, lia, 12a need more power than the power available from the CAN bus power lines 25, 26.
Example 6
It is now referred to fig. 6. This example is similar to example 5. However, here the second electric circuit 1 la is supplied with power from a battery 27, while the third electric circuit 12a is supplied with power from the CAN bus power lines 25, 26.
Example 7
It is now referred to fig. 7. Fig. 7 corresponds to fig. 2, but here three modules 10, 11 and 12 are shown. Here, the first module 10 may communicate both via CAN communication on lines 23, 24, and via HomePlug communication on CAN power lines 21, 22. The second module 11 may only communicate via HomePlug communication via CAN power lines 21, 22, while the third module 12 may only communicate via CAN communication lines 23, 24. Hence, in this example, the second and third modules 11, 12 may not communicate directly with each other, they may only communicate through the first module 10.
Example 8
It is now referred to fig. 8. Fig. 8 corresponds to fig. 1, but here, a third line 28 is shown in addition to the first and second lines 21, 22. The first and second lines 21, 22 may here be power lines, for example power lines of a cable. The third line 28 may be a neutral line of a cable. The HomePlug standard allows the use of such a third line 28 for HomePlug communication in addition to the first and second lines 21, 22.
The third line 28 may, or may not, be connected to the first and second electric units (10a, lia).
Example 9
It is now referred to fig. 9. Here, two modules 10, 11 each comprise a HomePlug communication unit 10b, 11b for communication by means of the HomePlug standard via first and second lines 21, 22.
In addition, the two modules 10, 11 each comprises a second power line communication unit 10c, lic for communication by means of a second power line communication protocol via first and second lines 21, 22. One such communication protocol may for example be the FMC proprietary MRM power line communication protocol. While HomePlug communition are using frequency bands in the MHz area, the MRM power line communication protocol is using frequency bands in the kHz area.
The embodiment in fig. 9 has been tested, and the two types of power line communications may be used simultaneously without interfering with each others communication.
It should be noted that the communication units 10c, lic may use other types of power line communication protocols, such as other proprietary types of power line communication
In the above examples, an internal communication line 30a, 30b, 31a, 31b, 32a are shown for communication between the respective HomePlug/Can communication units and the respective electric circuits. This communication may for example be Ethernet communication, Serial Peripheral Interface (SPI) bus communication or another type of communication system.
It has been found that HomePlug communication is robust and is suitable for communication on older power lines in subsea applications.

Claims (10)

1. Subsea system (1) comprising: - first and second lines (21, 22); - a first subsea module (10) comprising a first electric unit (10a); - a second subsea module (11) comprising a second electric unit (1 la); where the first subsea module (10) further comprises a first communication unit (10b) connected to the first electric unit (10a); where the second subsea module (11) comprises a second communication unit (11b) connected to the second electric unit (1 la); where the first and second communication units (10b, 11b) are connected to the first and second lines (21, 22); where the first and second communication units (10b, 11b) are configured to communicate with each other by means of power line communication.
2. Subsea system (1) according to claim 1, where the first and second communication units (10b, 11b) are configured to communicate with each other by means of the IEEE 1901 standard.
3. Subsea system (1) according to any one of the above claims, where: - the first subsea module (10) further comprises a first bus communication unit (10c) connected to the first electric unit (10a); - the second subsea module (11) further comprises a second bus communication unit (lic) connected to the second electric unit (Ha); - where the first and second bus communication units (10c, lic) are connected to bus communication lines (23, 24) of a communication bus.
4. Subsea system (1) according to claim 3, where the first and second bus communication units (10c, lic) are CAN bus communication units connected to CAN bus communication lines (23, 24) of a CAN communication bus.
5. Subsea system (1) according to claim 4, where the first and second lines (21, 22) are CAN power lines (GND, VDC).
6. Subsea system (1) according to any one of claims 1-4, where the first and second lines (21, 22) are power lines, and where at least one of the first and/or second electric unit (10a, lia) is connected to the first and second power lines (21, 22) for receiving electrical power via the first and second power lines (21, 22).
7. Subsea system (1) according to any one of claims 2-6, where the first communication unit (10b) and the first bus communication unit (10c) are configured to provide redundant or complementary communication with the second communication unit (11b) and the second bus communication unit (lic).
8. Subsea system (1) according to claim 1 or 2, where the first and second lines (21, 22) are communication lines, and where at least one of the first and/or second electric unit (10a, 10b) is connected to auxiliary power lines (25, 26) and/or a battery (27) for receiving electrical power via the respective auxiliary power lines (25, 26) and/or battery (27).
9. Subsea system (1) according to any one of the above claims, where the first and second electric units (10a, lia) are a sensor device, an actuator device, a battery device, a computer device, an AUV and/or control device.
10. Subsea system (1) according to any one of the above claims, where the system comprises a third line (28), where the first and second communication units (10b, 11b) are connected to the third line (28) and where the first and second communication units (10b, 11b) are configured to communicate with each other by means of the IEEE 1901 standard via the first, second and third lines (21, 22, 28).
NO20151765A 2015-12-21 2015-12-21 Subsea system NO20151765A1 (en)

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NO20151765A NO20151765A1 (en) 2015-12-21 2015-12-21 Subsea system

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2571453A (en) * 2018-02-27 2019-08-28 Ge Oil & Gas Uk Ltd Powerline interface communication

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US20050040709A1 (en) * 2001-08-31 2005-02-24 Thorsten Enders Method and supply line structure for transmitting data between electrical automotive components
US8199798B2 (en) * 2006-07-24 2012-06-12 Siemens Aktiengesellschaft Method and modem for subsea power line communication
EP2903172A1 (en) * 2014-01-31 2015-08-05 Melexis Technologies NV Apparatus and method for in-vehicle data transmission through power line

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Publication number Priority date Publication date Assignee Title
US20050040709A1 (en) * 2001-08-31 2005-02-24 Thorsten Enders Method and supply line structure for transmitting data between electrical automotive components
US8199798B2 (en) * 2006-07-24 2012-06-12 Siemens Aktiengesellschaft Method and modem for subsea power line communication
EP2903172A1 (en) * 2014-01-31 2015-08-05 Melexis Technologies NV Apparatus and method for in-vehicle data transmission through power line

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2571453A (en) * 2018-02-27 2019-08-28 Ge Oil & Gas Uk Ltd Powerline interface communication
GB2571453B (en) * 2018-02-27 2021-02-10 Baker Hughes Energy Tech Uk Limited Powerline interface communication

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