WO2009103737A1

WO2009103737A1 - Method and apparatus for determining location in a pipeline

Info

Publication number: WO2009103737A1
Application number: PCT/EP2009/051924
Authority: WO
Inventors: Jean Yves Satre; Robert Charles; Thierry Blanche
Original assignee: Enertag
Priority date: 2008-02-19
Filing date: 2009-02-18
Publication date: 2009-08-27
Also published as: GB0802992D0; GB2457661B; GB2457661A

Abstract

A system for determining the location of defects in a pipeline comprising; a pipe inspection tool for passing through the pipeline, comprising a reader and connectable to a pipe inspection device; a power supply for powering the pipe tool; a marker for placement on the outside of the pipeline, the marker being a passive tag powered by the in-line pipe inspection tool and comprising a transmitter to transmit date to the reader; wherein electromagnetic energy from the power supply of the pipe tool is provided to the marker and the marker can transmit data to the reader using ultrasonic communication; and a sensor located within the pipe tool for detecting the presence of the marker.

Description

Method and apparatus for determining location in a pipeline Technical field [0001] This invention relates to a method and system for detecting the location of defects in a pipeline.

Background art

[0002] Pipelines are regularly inspected from the interior of the pipe to detect defects, defaults, cracks and corrosion in the pipe. To inspect the inside of a pipeline a pipeline pig is positioned inside the pipe and passed down the pipe. The pigs can measure wall thickness and locate potential points of failure.

[0003] During the inspection of subsea pipelines a number of methods can be used to detect the location of the defaults in the pipe during the pigging run. This includes recording the distance traveled by the pig and then using this distanced traveled to determine the location of the part of the pipeline that needs repairing. Alternatively the location of defects can be determined by the counting of welds of the pipeline from a reference point by pig from the interior of the pipeline, to localize a defect to a weld and then counting the number of welds from the exterior of the pipeline to determine the location of the defect from the outside.

[0004] US20070194919 describes a method of localizing defects in a pipeline by using passive tags located on the outside of the pipeline. The pig counts welds which are visible from the inside of the pipeline, to localize a defect to weld. Near each weld a tag is located on the outside of the pipeline, containing an identification code specific to the pipeline and weld that it is associated with. A device is then used to read the tag from the outside of the pipeline to identify the weld associated with the defect.

[0005] However one of the problems that can occur is the accurate correlation of the results of the pig runs with external features and geodetic location. As a pipeline laid on a sea bed is not a straight line, repairs teams have difficulty in correlating the reported point of a defect identified by the pig with the actual geodetic location. In addition the location data retrieved from the pig can be inaccurate, i.e. the distance measured by the pig or the number of welds counted may be inaccurate, or the pipeline is covered by concrete making it difficult to accurately count the welds from the exterior of the pipeline. This can make it difficult, time consuming and costly to locate the actual point of repair. Disclosure of the invention [0006] Accordingly, a first aspect of the invention comprises a system for determining the location of defects in a pipeline comprising; a pipe tool for passing through the pipeline comprising a reader and connectable to a pipe inspection device; a power supply for powering the pipe tool; a marker for placement on the outside of the pipeline, the marker comprising a passive tag and a transmitter to transmit data to the reader; means for supplying electromagnetic energy from the power supply of the pipe tool to the marker to power the marker such that the marker can transmit information stored in the tag to the reader using ultrasonic communication; and a sensor located in the pipe tool for detecting the presence of the marker. [0007] Preferably the sensor is a magnetic field sensor and the marker comprises a permanent magnet. [0008] Preferably the system comprises electromagnetic coupling means to transmit power between the pipe tool and the marker. [0009] The power supply can be located in the pipe inspection device, alternatively the power supply can be located in the pipe tool. [0010] The marker can comprise a RFID tag and RFID reader. The marker further comprises a microcontroller for collecting data from the tag. [0011] The marker comprises an ultrasonic transmitter and the pipe tool reader comprises an ultrasonic receiver. [0012] A second aspect of the invention comprises a method for determining the location of a marker position on a pipeline comprising: detecting a marker using a sensor of a pipe tool connected to a pipe inspection device located in a pipeline providing electromagnetic energy from the power supply of the pipe tool to the marker located on the outside of the pipeline; activating a passive tag located in the marker; reading the tag data; and sending the data stored in the passive tag to the pipe tool by ultrasonic transmission.

[0013] Preferably the method uses the system as described above.

Brief description of the drawings

[0014] Figure 1 shows a schematic of the inspection tool and marker; and

Figure 2 shows a schematic of the detail of the inspection tool and marker.

Mode(s) for carrying out the invention

[0015] With reference to Figure 1 and 2 a marker 1 comprising a passive tag 2 is installed on the outside of a pipeline 3. A downhole pipe tool 4 is connected to a pipe inspection device such as a pig which is run inside the pipeline 3, such that it travels though the pipe with the pig. As the pipe tool 4 travels through the pipeline 3, when the pipe tool is in close proximity to the marker the pipe tool detects the presence of the marker 1 and electromagnetic energy from the power supply 5 of the pipe tool 4 is provided to the marker 1. This provides the marker 1 with enough power to be able to power the passive tag 2 located in the marker and to transmit the signal from the tag back to the pipe tool 4 by ultrasonic transmission and so that the marker 1 can be read from the inside of the pipeline 3. The tag 2 therefore is able to be read from both inside and outside of the pipeline 3.

[0016] As shown in Figure 2 the marker 1 comprises a RFID tag 2 and a RFID reader 6. The marker is a passive tag, i.e. it has no power supply or long- term power storage, and when the pipe tool is close to the marker electromagnetic energy from the power supply 5 of the pipe tool 4 is transmitted to the marker 1.

[0017] When the inline pipe tool 4 is close to a marker 1 a magnetic sensor 17 in the pipe tool will detect the magnetic field from a permanent magnet 18 in the marker. The sensor is connected to a microcontroller 19 in the pipe tool so that when the marker is detected the controller will trigger the power in the antenna coil 7 of the pipe tool to be switched on. This will allow electromagnetic coupling between the pipe tool and the marker to occur. Using the magnet to allow the marker to be detected by the pipe tool allows the marker to use minimum energy to be detected. However other sensor methods may be used. Once detected electromagnetic energy can be transmitted to the marker to supply the marker with enough power to enable the passive tag to operate.

[0018] Electromagnetic coupling between the antenna coil 7 of the pipe tool 4 and the antenna coil 8 of the marker 1 will occur when the antenna coil 8 of the marker 1 comes into range of the antenna coil 7 of the pipe tool 4 as the pipe tool moves through the pipeline 3. The electromagnetic coupling induces a voltage in the marker 1 which can be used to create a power supply 16 in the marker to provide power to the microcontroller 9 of the marker which in turn activates the RFID reader 6. With the RFID reader 6 powered the antenna 10 of the reader 6 will generate an electromagnetic field which induces a voltage in the antenna 11 of the RFID tag 2. This activates the tag 2 and provides the tag with enough power to be able to transmit the data back to the reader 6. The reader 6 can then transfer this data to the microcontroller 9. From the microcontroller 9 the data is encoded, amplified and transmitted to the pipe tool 4 through ultrasonic transmission.

[0019] The microcontroller 9 is connected to a transmitter 12. The transmitter 12 will send the information received from the tag 2 to a receiver 13 in the pipe tool 4. The transmitter 12 can be an ultrasonic transmitter and the receiver 13 an ultrasonic receiver. The information can then be transmitted from the pipe tool 4 to the pig via the microcontroller 19. Conventional recording means 14 within the pig store the location signals from the RFID. The data stored within the recording means of the pig can include the responding signals from the RFID and the data describing flaws detected by the pig during its operation, such that the markers external position can be correlated with the pig's internal location. Other data that can be recorded by the pig includes distance run, weld number of the pipeline, Alternatively the data can be stored in recordings means of the transceiver, with data recorded by the pig transmitted to the pipe tool. The data is downloaded after the pig and attached pipe tool is recovered from the pipe line and the data is examined to determine if any defects are found in the pipeline and they can be associated with a particular position, as signaled by the nearest RFID tag, where the defect was detected. The pig may detect defects in the pipeline using any known means, and may record defects by photos, videos, measurements etc.

[0020] Using the power of the pipe tool to activate the marker provides the marker enough energy to send its data through the concrete and metal wall 15 of the pipeline separating the marker outside the pipeline from the reader inside of the pipeline. The inline pipe tool may have its own power supply such as an internal battery, or alternatively the pipe tool is supplied with power from the pig.

[0021] A plurality of markers will be located on the outside of the pipeline. As the inline pipe tool passes through the pipeline and detects the magnetic field produced by the permanent magnet of the marker electromagnetic energy provided from the pipe tool power supply is passed from the pipe tool to a marker by electromagnetic coupling.

[0022] This allows the tags to be installed on the outside of the pipeline rather than being embedded in the pipelines during installation. As each marker is positioned on the exterior of the pipeline each individual marker is associated with a known particular geodetic point, the invention allows the correlation of an interior position with a known exterior geodetic point. As the inline pipe tool passes through the pipeline the reader of the pipe tool can identify the marker from the interior of the pipe and record in its log, the marker reference and its interior location.

[0023] Being able to associate an interior location with a known exterior geodetic makes it useful to locate the precise spot where damaged may have occurred in the pipeline. From the results of the pigging run the maintenance team will know what marker that a defect is associated with. The maintenance team can read the markers from outside the pipeline using conventional passive tag readers to find the exact marker that the defect is associated with, without the need to rely on the counting of welds, which can be inaccurate, to find the right section to repair. This will reduce the time that pipeline inspectors have to spend locating the spot on the pipeline that need repairing. [0024] The markers can be installed can be installed every kilometer along the pipeline however, other frequencies may be used, they may be installed any where along the line and do not have to be associated with a weld visible in the inside of the pipeline. If large distances occur between the markers of the invention, these may be combined with other known passive tags used, such that described in US20070194919, which can additionally be installed every four pipe section or 48m along the line.

[0025] Although the invention is described with reference to subsea pipelines, the invention is useful in any situation where the pipelines are located in difficult to reach places. Changes can be made while still remaining within the scope of the invention. For example, the tag may include some form of a power supply or long-term power storage means which operate in conjunction with or as an alternative to the power supplied by the pipe tool. In this case, the passive tag is partially or pseudo passive in nature. However, the aim of this invention, to provide power from the pipe tool to allow the tag to communicate, remains the same.

Claims

1. A system for determining the location of defects in a pipeline comprising; a pipe tool for passing through the pipeline comprising a reader; the tool connectable to a pipe inspection device; a power supply for powering the pipe tool; a marker for placement on the outside of the pipeline, the marker comprising a passive tag and a transmitter to transmit data to the reader; means for providing electromagnetic energy from the power supply of the pipe tool to the marker to power the marker such that the marker can transmit data stored in the tag to the reader using ultrasonic communication; and; a sensor located within the pipe tool for detecting the presence of the marker.

2. A system according to claim 1 wherein the sensor is a magnetic field sensor and the marker comprises a permanent magnet.

3. A system according to claim 1 or 2 wherein electromagnetic coupling is used to transmit power between the pipe tool and the marker.

4. A system according to any of claim 1 , 2, or 3 wherein the power supply is located in the pipe inspection device.

5. A system according to any of claim 1 , 2 or 3 wherein the power supply is located in the pipe tool.

6. A system according to any preceding claim wherein the marker comprises a RFID tag and RFID reader.

7. A system according to any preceding claim wherein the marker comprises a microcontroller for collecting data from the tag.

8. A system according to any preceding claim wherein the marker comprises an ultrasonic transmitter.

9. A system according to any preceding claim wherein the reader of the pipe tool comprises an ultrasonic receiver.

10. A method for determining the location of a marker position on a pipeline comprising: detecting a marker using a sensor of a pipe tool connected to a pipe inspection device located in a pipeline; providing electromagnetic energy from the power supply of the pipe tool to a marker located on the outside of the pipeline; activating a passive tag located in the marker; reading the tag data; and sending the data stored in the passive tag to the pipe tool by ultrasonic transmission.

11. A method according to claim 10 comprising using the system according to any of claims 1 to 10.