WO2015114096A2

WO2015114096A2 - Pipeline system for transporting fluids

Info

Publication number: WO2015114096A2
Application number: PCT/EP2015/051935
Authority: WO
Inventors: John Bo Nielsen; Hans LA COUR HARBO
Original assignee: John Bo Nielsen
Priority date: 2014-01-31
Filing date: 2015-01-30
Publication date: 2015-08-06
Also published as: WO2015114096A3

Abstract

A pipeline system for transporting fluids comprising: - at least a first pipe section and a second pipe section. Each pipe section has a first end and a second end. The first end of the first pipe section is coupled in a fluid communication with the second end of the second pipe section at a joint between the first and the second pipe section. A conductive material of the first pipe section is in electrical communication with the conductive material of the second pipe section providing a continuous electrical communication from the second end of the first pipe section to the first end of the second pipe section. - at least one detection module that is positioned close to the intersection between the first and the second pipe section and the detection module is in electrical communication with the conductive material of the first and/or the second pipe section; a power source positioned at one end of the first or the second pipe section in electrical communication with the conductive material of the pipe sections to provide an electrical current in waves at a predefined wavelength to provide power to the at least one detection module; the detection module comprises a first electrical terminal and a second electrical terminal, so that the detection module is capable of harvesting energy from the amplitude difference between the first and the second electrical terminal.

Description

Pipeline system for transporting fluids.

The present invention relates to a pipeline system for transporting fluids comprising:

-at least a first pipe section and a second pipe section, wherein each pipe section has a first end and a second end where the first end of the first pipe section is coupled in a fluid communication with the second end of the second pipe section at a joint between the first and the second pipe section, and where each pipe section comprises a conductive material that extends between the first end and the second end of the pipe section, where the conductive material of the first pipe section is in electrical communication with the conductive material of the second pipe section providing a continuous electrical communication from the second end of the first pipe section to the first end of the second pipe section;

-at least one detection module that is positioned close to the intersection between the first and the second pipe section and where the detection module is ar- ranged to detect status and/or irregularities with or near the joint and/or the pipeline, the detection module is in electrical communication with the conductive material of the first and/or the second pipe section;

-a power source positioned at one end of the first or the second pipe section in electrical communication with the conductive material of the pipe sections to provide an electrical current in waves at a predefined wavelength to provide power to the at least one detection module.

Furthermore, the present invention relates to a method of manufacturing a pipeline system wherein the method comprises the steps of:

- providing at least a first and a second electrically conductive pipe section, - joining the at least two pipe sections,

- attaching a power source, e.g. a standing wave generator, to the first and/or second pipeline section for supplying power to a detection module, and

- attaching a detection module to the first and/or second pipeline section, said detection module arranged for detection of fluid and said detection module is arranged in such way that the detection module harvest power from the power source,

- providing a receiver for receiving signals from the detection module superimposed on the wave from the power source. BACKGROUND

Since oil and gas pipelines are important assets of the economic development of almost any country, it has been required either by government regulations or internal policies to ensure the safety of the assets, and the population and environment where these pipelines run. Furthermore, the pipelines are used for e.g. district heating pur- poses having a central power plant supplying heating for e.g. cities. In the following, mostly the use of pipelines for oil and gas is discussed, but the same principles apply for the use in relation to pipelines in a district heating grid from a central power plant.

Pipeline companies face government regulations, environmental constraints and social situations. Pipeline companies should comply with government regulations, which may dictate various issues from minimum staff to run the operation, operator training requirements, up to specifics including pipeline facilities, technology and applications required to ensure operational safety. For example, in the State of Washington, it is mandatory for pipeline operators to be able to detect and locate leaks of 8 percent of maximum flow within 15 minutes or less. The social situation also affects the operation of pipelines. In third world countries, product theft is a problem for pipeline companies. It is common to find unauthorized extractions in the middle of the pipeline. In this case, the detection levels should be under 2 percent of maximum flow, with a high expectation for location accuracy.

Different types of technologies and strategies have been implemented, ranging from physically walking the lines to satellite surveillance. The most common technology to protect these lines from occasional leaks is known as Computational Pipeline Monitoring Systems or CPM. CPM takes information from the field related to pressures, flows, and temperatures to estimate the hydraulic behavior of the product being transported. Once the estimation is done, the results are compared to other field references to de- tect the presence of an anomaly or unexpected situation, which may be related to e.g. a leak.

The part actually carrying the fluid to be handled e.g. a metal inner tube is often encased by a jacket. The area between the jacket and such metal inner tube is often filled with an insulation material. The metal inner tube may be surrounded solely by a jacket i.e. having no insulation filing the cavity between the metal inner tube and the jacket.

FR2408788 discloses a pipeline system having a leak detection system. The communication is carried out from module to module where one module is amplifying the signal and the final module communicates to base station. Each module is connected to the ground. The transmitted and received signals are carried via the tube of the pipeline system. The system is wired/connected to earth.

Hence, there is a need for at pipeline system having a detection system that is easier to power and install.

Furthermore, there is a need for at pipeline system that is configurable to measure and/or detect various parameters.

Furthermore, there is a need for a pipeline system in which the insulation and/or the jacket of the pipe sections are not penetrated by wiring to e.g. a leak detection system.

The drawbacks mentioned above is at least partially overcome according to the present invention by providing a pipeline system for transporting fluids comprising: -at least a first pipe section and a second pipe section, wherein each pipe section has a first end and a second end where the first end of the first pipe section is coupled in a fluid communication with the second end of the second pipe section at a joint between the first and the second pipe section, and where each pipe section comprises a conductive material that extends between the first end and the second end of the pipe section, where the conductive material of the first pipe section is in electrical communication with the conductive material of the second pipe section providing a continuous electrical communication from the second end of the first pipe section to the first end of the second pipe sec- tion;

-at least one detection module that is positioned close to the intersection between the first and the second pipe section and where the detection module is arranged to detect status and/or irregularities with or near the joint and/or the pipe section, the detection module is in electrical communication with the conductive material of the first and/or the second pipe section;

-a power source positioned at one end of the first or the second pipe section in electrical communication with the conductive material of the pipe sections to provide an electrical current in waves at a predefined wavelength to provide power to the at least one detection module;

characterised in that,

-the detection module comprises a first electrical terminal and a second electrical terminal, where said first and second electrical terminal is in electrical communication with the conductive material of the first and/or the second pipe section and where the first electrical terminal is positioned at a predefined distance from the second electrical terminal in the longitudinal direction of the pipe section, such that the first terminal intersects the wave of electrical current at a different amplitude than the second electrical terminal so that the detection module is capable of harvesting energy from the amplitude difference between the first and the second electrical terminal.

It is to be understood by the person skilled in the art that the pipeline system may carry a fluid, gas, or liquid or mixed products. By harvesting energy from the power source in this way, it is achieved that no specific wires extending from the power source to the detection module for powering the detection module, is necessary. The harvesting principle is to be understood as absorbing/utilizing or being powered by the energy. This is an advantage, both during manufacturing as well as during the installation of the pipeline/pipe sections. The wire typically extends along the longitudinal axis of the pipe section, the wire(s) being positioned between the layer of insulation and the pipe itself. The handling of such wire is costly and difficult during the insulation process and hence, the manufacturing process is strongly eased when handling of such wire along the full length of the pipe sections is avoided. At the construction site of which the pipe sections are to be installed, i.e. connected, e.g. by welding, to another pipe section, it is furthermore not necessary for the workers to handle wires for detection systems. Such wires along the full length of the pipe sections, as shown in prior art, need to be kept fully clear of the welding process during assembly of the sections and after assembly the wires need to be assembled, which in itself is a time demanding process. However, in order to ensure the full functioning of the detection system it needs to be tested thoroughly before applying insulation that covers the outer surface of the inner pipe. The inner pipe being the actual tube/pipe in which the fluid to be transported flows. Typically, the end parts of the inner pipe of pipe sections are kept free of insulation from the factory in order to attach the pipe sections e.g. by welding. The prior art detection systems need to be coupled together near the joint of two pipe sections i.e. demanding the handling of the wires for the detection system. This is time consuming, as on site tests of the functionality must be carried out. Factory insulated pipe sections are often referred to as preinsulated pipe sections. The present invention provides a detection module that can be mounted and tested during the pipe section manufacturing process. The detection modules may be welded or otherwise attached to the pipe during the manufacturing process and leaves no issues concerning the detection module to be handled by the worker. In particular, the worker needs not to handle wires of any kind. Hence, it is not necessary for the worker at the installation site of the pipe section to cause a halt of any kind e.g. for testing or connecting the detection module, of the large entrepreneurial process it is to install pipe section. Even if the pipeline system of the present invention has the detection module mounted on sited still no wires are to be handled. This is due to the fact, that harvesting the energy via the pipe section itself only requires that the first and the second electrical terminal of the detection module are spaced just a few centimetres from each other. The distance between the first and the second electrical terminal is determined in detail by the wavelength emitted by the power source. Hence the detection module is a relatively small unit that can be at- tached to the pipe before the insulation is applied without affecting neither the properties of the insulation nor the manufacturing process itself. If desired, the detection module may be installed e.g. welded onto the pipe at location. This could e.g. be the situation if more detection modules than initially thought necessary is required e.g. due to more harsh environment than initially expected. During the installation process on site, no wires are to be handled by a unit to be welded (or soldered) onto the pipe. Hence, the specific expertise needed from a worker to perform the operation is practically always present on the construction site and no valuable time is spent awaiting the arrival of proper skilled worker e.g. an electrician. The detection module is arranged such that an alternating voltage difference is developed across the two terminals. This voltage difference is a consequence of the two terminals being at different phase an- gles relative to the electrical waveform generated by the power source along the pipe- sections. Because of this voltage difference, it is achieved that the detection module can harvest energy from the pipeline system.

In an embodiment of the invention the detection module may comprise a transmitter device.

In order for the detection module to not only detect but also to send the values measured to a remote location, e.g. a monitory facility, the detection module may comprise a transmitter device. The transmitter device may enable the detection module to report both a status and to report in case a situation of a certain kind has been detected, e.g. reporting in case of a leak, vibrations or an unexpected drop in temperature. In an embodiment of the invention the detection module may comprise a number of electrical terminals.

In an embodiment of the invention the transmitter device may be in electrical communication with the first and/or the second electrical terminal to provide a signal transmis- sion along the electrical conductive material of the first and/or the second pipe section.

By using the electrical conductive material of the first and/or second pipe section to provide a transmission line, it is achieved that no separate wiring is necessary along the pipe sections for said purpose. Hence, the installation of the detection module is not in any way altered or made more complicated in order for the detection module to be able to transmit as well as detect. The pipe sections may be solely a metal inner tube or further comprise a jacket and/or insulation. In an embodiment of the invention the transmitter may send signals as superimposed signals on the wave from the power source. The frequency may be in the range of 2 - 10.000 or more specifically 5 - 5.000 or more specifically 10 - 2.500 or or more specifically 15 - 1 .250 times higher than the frequency of the power source. In this way the signals are easy to distinguish from the power source signal. In an embodiment the system may comprise a monitoring facility. In this way the signals, data packages, from the transmitters in the detection modules can be received and evaluated. In an embodiment of the system the monitoring facility comprises a high-pass filter for filtering the voltage from the transmitter (transmission line) and decoding the high frequency data transmitted from the detection module. In an embodiment of the invention the predefined distance between the first and the second electrical terminal may be in the range between 0,1 and 1 ,9 of the predefined wavelength of the electrical current, more specifically between 0,2 and 1 ,5 of the predefined wavelength, more specifically between 0,3 and 1 of the predefined wavelength, or more specifically at 0,5 wavelength.

At this distance it is achieved that most of the detection modules are arranged to harvest as much energy as possible. It is to be understood that the situation for which it is possible to harvest the most energy from sinusoidal wave is at a wavelength of 0,5 of the power source wavelength in the position of which the slope is 0 i.e. the differential coefficient is 0. This is the position having the largest potential difference.

In an embodiment of the invention the first and/or the second pipe section may be an insulated pipe comprising: a metal inner tube, an insulation layer surrounding the metal inner tube and an outer protection jacket.

A standing wave is applied to the inner tube of metal and therefore the inner metal tube, acting as a transmission line, is the line of which the detection module harvests energy. Furthermore, in order to retrieve the measured status by the sensor, the detection module uses the transmission line, i.e. the inner metal tube, for reporting to the monitoring facility by injecting a high frequency signal, a superimposed signal on the standing wave. In case of e.g. a leak in a pipe section having such build-up, the leak will typically spread out between the metal inner tube and the insulation layer surrounding the metal inner tube. In this way it is possible to determine a leak within the length of the distance between two detection modules. This means that the higher the number of detection modules per length unit the higher an accuracy is achieved. The detection module may comprise a unique identification number and by this it is possible precisely to identify the detection module sending out a detection signal falling outside of the desired range.

In an embodiment of the invention the detection module may be positioned between an outer surface of the metal inner tube and the insulation layer.

In this embodiment the detection module is attached to the outer surface of the metal inner tube and when the installation is finalised the detection module is surrounded by insulation except from the part of the detection module facing the inner tube of metal. In this way it is achieved that the electrical terminals of the detection module are provided with the possibility of direct contact to the metal inner tube. Furthermore, the detection module is positioned between the insulation and the metal inner tube i.e. in the location in which any leaks from the inner metal tube are most likely to spread out. Typically if a leak is occurring the fluid will spread out from the actual leak, i.e. the hole in the inner tube, between the insulation layer and the inner metal tube. Hence, this is the most likely place to detect leaks.

In an embodiment of the invention the electrically conductive material may be the metal inner tube of the first and/or the second pipe section.

Using a metal inner tube facilitates that the metal inner tube can be used as transmission line for supplying energy to the detection module. Furthermore, the metal inner tube is used for transmission of the signals from the detection module.

In an embodiment of the invention the metal inner tube of the first and/or the second pipe section may be made of steel, stainless steel, PG235Tr, AISI 304, AISI 316, Duplex, SuperDuplex, or generally of a martensite material. In another embodiment the metal inner tube of the first and second pipe section may be made of a composite conductive polymeric material e.g. a polymeric having added a conductive coating.

In this way it is achieved that the metal inner tube is capable of conducting energy to the detection module. Furthermore, it is possible for the detection module to transmit signals to a monitoring facility.

In an embodiment of the invention the power source may be a standing wave generator.

In similar embodiment the power source may also be considered an alternating current or voltage source, said power source feeding the pipe line with a sinusoidal signal. When using a standing wave generator as a power source it is achieved that a constant signal is present for the detection module to harvest from. Furthermore, the constant nature of the standing wave simplifies the process of detecting the signals transmitted from the detection modules. The power needed to power the detection modules is determined by way of the transmission line theory by setting the parameters of e.g. pipe diameter, pipe material, type of fluid in the pipe, number of detection modules per power source, distance between power sources, frequency and amplitude of the signal generated by the power source(s). The system may comprise a number of amplifiers along the pipeline. These amplifiers may both amplify the signal as well as re-shape the signal. The power source may supply the pipeline system with 5 - 100kW. The current needed for the power source for powering the detection modules of a pipeline system may be 10-1000 Amps or the interval 12-500Amps or in another embodiment the interval 14-250 Amps or in the interval 16-125 Amps or in the interval 18-65 Amps in order to power the detection modules. In an embodiment of the invention the pipeline system may comprise a number of power sources. If more power sources a are used the power sources will ad additional power along the pipeline system in order to maintain the power need for the detection modules to function. If the pipeline system comprises more than one power source the power of each power source of the pipeline system is reduced.

In one embodiment of the invention a pipe section system may only partly comprise an insulating and/or jacket layer.

In this way a simpler and less costly pipeline section i.e. pipeline system is provided. In another embodiment the pipeline system may only comprise the metal inner tube and an outer jacket layer i.e. an embodiment without the insulating layer.

Furthermore, it is an aspect of the invention to provide a detection module for detecting a fluid used in a pipeline system.

In one embodiment the detection module sensor may comprise a transducer. In an embodiment of the invention the detection module may use 2μ\Λ - 5W, or 2,5μ\Λ -2,5νν or more preferred 3μ\Λ - 1 ,25W or more preferred 3,5μ\Λ to 0.75W or most preferred 4μ ν to 375mW.

The transducer is capable of being adapted to a large number of purposes. Therefore, by using a transducer, it is achieved that the detection module may detect not just one but several parameters e.g. fluid, vibration, pressure, temperature etc. The transducer may be adapted to the specific purpose. Furthermore, it is an aspect of the invention to provide a method of detecting a fluid wherein the method comprises the steps of:

- providing a standing wave for powering a detection module,

- measuring a fluid level by a sensor in the detection module, - transmitting the measured level of fluid to a receiver using a signal superimposed on the standing wave.

In this way it is achieved that the detection module functions without necessitating wires along the full longitudinal axis of the pipeline for powering the detection module as well as for transmitting the measured values from the detection module. The detec- tion module does not rely on batteries that at some point need changing. Replacing the batteries in a device similar to the detection module of the present invention is a highly costly process, in particular if the pipeline system is submerged either in the sea or buried under ground. This is also the case when considering district heating pipeline systems. Furthermore, it is an aspect of the invention to use the pipeline system for detection of fluid along pipelines e.g. oil pipes, gas pipes and pipes for district heating.

In this way the detection of fluid may be carried out in a cheaper and more accurate manner. Furthermore, the installation process is cheaper because the handling of the detection device is easy and the cost for wiring along the full length of the pipeline is avoided.

Furthermore, it is an aspect of the invention to provide a method of manufacturing a pipe system wherein the method comprises the steps of:

- providing at least a first and a second electrically conductive pipe section,

- joining the at least two pipe sections, - attaching a power source, e.g. a standing wave generator, to the first and/or second pipeline section for supplying power to a detection module, and

- attaching a detection module to the first and/or second pipeline section, said detection module arranged for detection of fluid and said detection module is arranged in such way that the detection module harvest power from the power source, - providing a receiver for receiving signals from the detection module superimposed on the wave from the power source.

In this way a system is achieved in which the communication as well as the power supply for the detection module is carried out without connecting the detection and the power source by wires. The wires necessary in many detection systems are trouble- some and expensive to handle during the manufacturing and installation of the pipe sections in order to form a pipeline system. A set of electrical terminals for harvesting power from a standing wave may be arranged in a manner that requires a minimal effort of work during installation. The detection module and the electrical terminals may be considered as one unit. In this way the handling by the worker installing the detec- tion module is eased.

In an embodiment of the invention the method of manufacturing a pipeline system may further comprise the step of insulating the at least two pipeline sections. In an embodiment of the invention the detection module holds a beacon function to transmit a unique message confirming that the detection module is fully functional. Due to the fact that the detection module does not need wires in order to be provided with power, the detection module may be mounted on the pipe section at any time e.g. before the main part of the pipe section is factory fitted with insulation or during the on- site joining of two pipe sections. This is achieved because the detection module is small enough to be positioned at the end part of a pipe section kept free of insulation in order to join the pipe section to a subsequent pipe section. Alternatively, the mounting of the detection module at the end part of a pipe section may be carried out during the manufacturing of the pipe section. In such case the workers joining the pipe sections to form a longer pipeline do not need to consider the presence of the detection module. The workers need only to fit the insulation in an ordinary manner after having joined two sections, typically by welding. In fact, if the detection module is mounted at the fac- tory, the workers installing the pipe sections on the site of use, will not even notice the presence of the detection module during the installation process of the pipe sections.

Likewise, a detection module is capable of transmitting measured values to a monitoring system without the use of wires and for similar reasons as mentioned above the worker is free of any considerations concerning wires for the detection module and hence, the same advantages as above apply i.e. that attaching the detection module may be carried out at different points in the manufacturing process. In an embodiment of the invention the pipeline system may comprise more than one detection module at the same axial location. In this way a back-up detection module is present in case the first fails or malfunctions. Similarly, at least one additional detection module at the same axial position may be present at a location of the pipeline of particular interest. In this way, it possible not only to have a back-up detection module, but a second (or more) detection module(s) being in service at the same time as the first detection module. This may be detection modules adapted to a particular task. In an embodiment the additional detection module(s) may be activated from the distance. In this way the additional detection module(s) is causing minimal energy consumption to be delivered from the power source. In an embodiment of the invention the detection module may further comprise means for carrying measuring concerning flow using Doppler technique (effect) e.g. by means of a sound or radar transmitter encircling the inner tube of the pipe- line at specific locations. In an embodiment of the pipeline system the inner tube may comprise an annular indent. In this way a leak radially opposing the position of the detection module may be forwarded faster to the sensor of the detection module. Likewise, the detection module may comprise a number of sensors positioned at different annular locations. During the installation of a detection module an identification e.g. a bar code may simply be scanned and compared with the exact gps location of the detection module. In this way the detection module is fully positioned and hence simple to position if it detects a malfunction e.g. a leak.

It will be understood, that the "wires" discussed concerning prior art concerns wires ex- tending substantially along the full length of a pipe section or at least along a major part of the pipeline / pipe section. The detection module of the present invention may contain smaller wire segments used in an ordinary matter in relation with the electrical components. The present invention primarily describes pipeline systems comprising straight pipeline sections having no branches. However, it is to be understood that the system may be used for branched sections as well.

BRIEF DESCRIPTION OF DRAWINGS The invention is explained in detail below with reference to the drawings, in which

Fig. 1 shows the general components of an embodiment of a pipeline system according to the invention, the shown system comprising three pipe sections,

Fig 2 shows in a schematic view an embodiment of a build-up of a detection module,

Fig. 3 shows a schematic view of a the positioning of detection modules in relation to the power source, and

Fig. 4 shows the schematic view of Fig. 3 having introduced a superimposed signal on the power signal.

DETAILED DESCRIPTION OF DRAWINGS

Fig. 1 shows a pipeline system 1 comprising three pipe sections 2, 2^', 2^" (the three pipe sections 2, 2^', 2^" are uniform and only where necessary for the reader to distinguish between the three pipe sections are they individually numbered. Otherwise, for like parts of the three pipe sections like reference numerals are used). The pipe section s 2, 2^', 2^" are all depicted as cut at the middle in order to indicate that the pipe sections 2, 2^', 2^" are in fact longer. Each pipe section 2, 2^', 2^" has a first end part 3, 3^', 3^" and a second end part 4, 4^', A^". The pipe sections 2, 2^', 2^" further comprising insulation material 5 and a jacket 6. The system further comprises a power source 13 and a monitoring facility 12. The pipe section length t1 indicates the length of a single pipe section 2, 2^', 2^" e.g. 16 meters. The length of a pipe section may typically be 6 meters 12 meters or 16 meters. However, the length of the pipe sections 2, 2^', 2^" may vary from supplier to supplier and according to the specific needs. The first end 3, 3^', 3^" and the second end 4, 4^', A^" of the pipe sections comprise an end part having no insulation material 5 nor jacket 6 at this point in the installation process of pipeline sys- tem 1 . The end parts of the pipe sections are left with no insulation material from the factory in order to facilitate that it is possible to join the pipe sections 2 with 2^' at joint 7 i.e. by joining e.g. by welding the inner tube 9 with inner tube 9^'. Similarly, pipe section 2^' is joined with 2^" at joint 8 i.e. by joining inner tube 9^' with 9^". This joining of the sec- tions is typically carried out by welding them together. Between the rim of the second end part 4 of the first pipe section 2 and the radially extending end face 15 of the factory fitted insulation 5 a detection module 10 is attached (shown in an enlarged sectional view also). The detection module 10 comprises a first electrical terminal A and a second electrical terminal B. The terminals A, B are spaced a distance 12 apart. The dis- tance 12 is determined according to the wavelength generated by the power source 1 1 generating a standing wave for the detection module 10 to harvest energy from. The distance 12 is substantially half a wavelength generated by the standing wave generator 1 1 . At this distance of 12 it is possible to harvest the most energy from the standing wave. The terminals A, B are attached to the inner tube 9 in a manner ensuring a firm electrical contact e.g. by welding or by soldering. The actual casing of the detection module 10 needs only to be glued or in similar manner attached to the inner tube 9. It is to be understood that the detection module 10 may be discussed as comprising the electrical terminals A, B. However, in order to better visualize and describe the location of the electrical terminals A, B, the terminals A, B are depicted and discussed as sepa- rate items. The electrical terminals A, B will be arranged in a manner that requires a minimal effort of work during installation. The detection module 10 and the electrical terminals may be considered as one unit. In this way the handling by the worker installing the detection module including the electrical terminals A, B is eased.

The standing wave generator 1 1 , a wave form generator, is in fact an AC source. In or- der to obtain the desired characteristics of the standing wave the amplitude and the frequency are adjusted. In order to carry the standing wave the electrically conductive inner tube 9 acts as a transmission line. Using the inner tube 9 as a transmission line the necessity of wires along the pipe sections 2, 2^', 2^" is avoided.

Fig. 2 shows a block diagram of a build-up of an embodiment of the detection module 10. In the following each component/ block and its characteristics will be described in further detail. Connections depicted with single lines represent power. Connections depicted with triple lines are signals and finally, connections depicted with double lines represent the interface to the pipe section 2 having the two electrical terminals A, B located at a predefined distance apart.

The TX/RX switch 20 determines if the two terminals A, B are connected to the rectifier 25 for power harvesting or connected to the transmitter module 22 for sending a signal 32 to the monitoring facility 12. The TX/RX switch 20 may be either passive or active and autonomously configures for transmission with a signal from the transmitter mod- ule 22 is detected. The electrical terminals A, B are for illustrative purposes shown outside the detection module 10, but are to be considered as comprised in the detection module 10.

A rectifier 25 is used when an alternating signal is experienced between the two termi- nals A, B. When the signal is experienced the signal is rectified to feed power to the energy manager 26.

The energy Manager 26 handles charging and discharging of the energy storage 27 and distribution of regulated power to the other functional modules.

The energy storage module 27 facilitates energy storage in the form of e.g. a battery, bank of capacitors or a supercapacitor. Due to the reliability requirements and life-time requirements the latter two options may be preferred over a battery based solution. The sensor 30 is the sensor for sensing the status of the desired feature e.g. a leak sensor or a temperature sensor or both - depending on the desired features to be measured. A large number of sensors are to be implemented in the system and hence the system is adaptable to a large variety of sensors 30. The Logic Unit (LU) 35 executes the decision logic in order to determine if an alarm signal should be transmitted. Furthermore, the logic unit 35 implements self-testing and reporting of the detection module 10. Each LU 35 is precoded with a unique detection module 10 identifier for identification and localisation purposes. The transmitter 22 encodes and transmit the high frequency signals to the monitoring facility 12 whatever this is e.g. a daily or weekly status message or an alarm message.

The detection module 10 may be based on a single chip solution designed specifically for the application in question.

Fig. 3 shows the general depiction of the pipeline system shown in Figure 1 , but in Fig. 3 a coordinate system 30 is introduced in order to show the standing wave 31 and how the standing wave 31 is used in the system. The coordinate system 30 have voltage as the second axis. A sinusoidal standing wave 31 is seen and how the signal is alternating along the length of the pipeline system 1 , i.e. along the longitudinal axis of the joint pipe sections 2, 2^', 2^". Thus, Fig. 3 is a schematic view of a power feeding principle i.e. how the power source 1 1 is providing the detection module 10 with power. It is seen that the distance 12 between the electrical terminals A,B of each detection module 10, 10^', 10^" is spaced half a standing wave 30 apart.

A waveform/wave generator 1 1 feeds an alternating signal (with respect to ground) 31 to the pipe section 2 i.e. to the metal inner tube 9. In this embodiment the waveform is a relatively low frequency waveform (power waveform). The metal inner tubes 9, 9^', 9^" are in electrical communication and therefore the alternating signal 31 is continued through the entire pipeline system 1 . Hence, the inner metal tubes 9, 9^', 9^" are considered as a conducting transmission channel. In this way it is achieved that the voltage curve across the pipeline system 1 , i.e. across the metal inner tubes 9, 9^', 9^", ideally looks as depicted on the graph 31 . Each detection module 10 is attached to the metal inner tube electrically with the first terminals A and the second terminal B at the predefined distance 12. By this arrangement, it is achieved that a voltage differential is present that can be exploited by the detection module 10 to harvest power by applying an electrical load across the terminals A, B. When considering the metal inner tube 9, 9^', 9^" as a transmission line the lowest transmission loss may be achieved when the standing wave 31 is generated across the metal inner tube.

Due to the standing wave 31 , each detection module 10 will see the same voltage differential at all times and this differential will be different for each unit depending on the location of the terminals relative to the sinus signal. This may result in some detection modules 10 having difficulty in harvesting sufficient energy because the particular location of the electrical terminals A, B are imprecisely positioned on the pipe section (i.e. out of phase) in relation to the optimal harvesting position i.e. in relation to the standing wave. However, this situation is overcome by maintaining the standing wave 31 phase in a way such as to allow/control it to drift slowly along the x-axis. In this way, it is obtained that all detection modules 10, 10^', 10^" have adequate conditions, i.e. adequate power to perform the desired tasks. As an example the electrical terminals A^", B^" not positioned at a location to harvest the maximal power from the standing wave 31 at the same time as the detection modules 10, 10^' have the opportunity to harvest the maxi- mal power from the standing wave 31 . As will be understood by the above, letting the standing wave 31 drift slightly to the right i.e. in the positive direction of the x-axis, the maximal amplitude is located at the optimal position for the detection module 10^", i.e. the electrical terminals A^", B^", to harvest power. Obviously, this causes the other two detection modules 10, 10^' to be able to harvest less power, but over time such drifting of the standing wave 31 equals the power for the detection modules in a way that sufficient power is present. As discussed previously (in relation to Fig. 2), the harvested power is stored in the energy storage 27.

Fig. 4 shows a depiction similar to Fig. 3, but with the focus on the transmitting signals 32, 32^', 32^" from the detection modules 10. The signals 32 are transmitted from the detection modules 10, 10^', 10^" by the transmitter 22 (only shown in Fig. 2) in each detection module 10. The signals are transmitted as superimposed signals 32, 32^', 32^" on the standing wave 31 . Each detection module has a unique identification that may be sent along with the signal 32 whereby it is possible to identify from which detection module 10, 10^', 10^" the signal 32, 32^', 32^" originates. The monitoring facility 12 collects the signals 32 and from this point decisions will be carried out in order to evaluate if or what actions should be taken. When considering a pipeline system 1 comprising a large number of detection modules 10 collisions of signals 32, 32^', 32^" from the detection modules 10 may occur. However, this may be overcome either by setting time slots in which each detection module 10 may transmit signals 32. The signals 32, 32^', 32^" may also be transmitted randomly. It is depicted by arrows that the signals 32 travel along both directions of the pipeline system 1 . Hence, if a second monitoring facility (not shown) is located at a different location said second monitoring facility will also be able to pick up all signals 32 emitted from the detection modules 10, 10^', 10^". It will be understood that the smaller the distance the detection modules 10 are spaced apart, the more detailed the monitoring of the pipeline will be. In the shown embodiment of the invention each detection module 10, 10^', 10^" covers a distance of if, i.e. covering approximately half a pipe section 2 on each side of a joint 7, 8. However, e.g. a leak spreading out from the middle of a pipe section 2^' may be detected by two detection modules 10, 10^'. If such event occurs the time span from the first module detecting the leak to the second detection module detecting the leak may assist in determining the exact location of the leak.

Claims

1 . A pipeline system for transporting fluids comprising:

-at least one detection module that is positioned close to the intersection between the first and the second pipe section and where the detection module is ar- ranged to detect status and/or irregularities with or near the joint and/or the pipe section, the detection module is in electrical communication with the conductive material of the first and/or the second pipe section;

characterised in that,

-the detection module comprises a first electrical terminal and a second electrical terminal, where said first and second electrical terminal is in electrical commu- nication with the conductive material of the first and/or the second pipe section and where the first electrical terminal is positioned at a predefined distance from the second electrical terminal in the longitudinal direction of the pipe section, such that the first terminal intersects the wave of electrical current at a different amplitude than the second electrical terminal so that the detection module is capable of harvesting energy from the amplitude difference between the first and the second electrical terminal.

2. A system according to claim 1 , wherein the detection module comprises a trans- mitter device.

3. A system according to claim 2, wherein the transmitter device is in electrical communication with the first and/or the second electrical terminal to provide a signal transmission along the electrical conductive material of the first and/or the second pipe section.

4. A system according to any of the preceding claims, wherein the predefined distance between the first and the second electrical terminal is in the range between 0,1 and 1 ,9 of the predefined wavelength of the electrical current, more specifically between 0,2 and 1 ,5 of the predefined wavelength, more specifically between 0,3 and 1 of the predefined wavelength, or more specifically at 0,5 wavelength.

5. A system according to any of the preceding claims wherein the power source is a standing wave generator.

6. A system according to any of the preceding claims wherein the first and/or the second pipe section may be an insulated pipe comprising: a metal inner tube, an insu- lation layer surrounding the metal inner tube and an outer protection jacket.

7. A system according to any of the preceding claims wherein the electrically conductive material may be the metal inner tube of the first and/or the second pipe section.

8. A system according to any of the preceding claims wherein the metal inner tube of the first and/or the second pipe section is made of steel, stainless steel, PG235TY, AISI 304, AISI 316, Duplex, SuperDuplex, or generally of a martensite material.

9. A detection module for detecting a fluid used in a system according to claim 1 - 8

10. A detection module according to claim 9, wherein the detection module sensor comprises a transducer.

1 1 . A detection module according to claim 10, wherein the detection module uses 2μ\Λ - 5W, or 2,5μ\Λ -2,5νν or more preferred 3μ\Λ - 1 ,25W or more preferred 3,5μ\Λ to 0.75W or most preferred 4μ\Λ to 375mW.

12. A detection module according to claims 9-1 1 , wherein the detection module is positioned between an outer surface of the metal inner tube and the insulation layer.

13. A method of detecting a fluid wherein the method comprises the steps of:

- providing a standing wave for powering a detection module according to claims 9 -12, - measuring a fluid level by a sensor in the detection module,

- transmitting the measured level of fluid to a receiver using a signal superimposed on the standing wave.

14. Use of a system according to claims 1 -8 for detection of fluid along pipelines.

15. A method of manufacturing a pipe system according to claims 1 -8, wherein the method comprises the steps of:

- providing at least a first and a second electrically conductive pipe section,

- joining the at least two pipe sections,

- attaching a power source, e.g. a standing wave generator, to the first and/or second pipeline section for supplying power to a detection module, and - attaching a detection module to the first and/or second pipeline section, said detection module arranged for detection of fluid and said detection module is arranged in such way that the detection module harvest AC-power from the power source,

- providing a receiver for receiving signals from the detection module superimposed on the wave from the power source.