AU3828500A

AU3828500A - Apparatus and method for determining the physical condition of a pipeline

Info

Publication number: AU3828500A
Application number: AU38285/00A
Authority: AU
Inventors: Anthony Yates
Original assignee: Copipe Systems Ltd
Current assignee: Copipe Systems Ltd
Priority date: 1999-04-10
Filing date: 2000-04-10
Publication date: 2000-11-14
Also published as: GB9908139D0; EP1171248A2; GB0027108D0; GB2365504A; NO20014912L; WO2000061305A2; BR0009687A; GB2365504A8; NO20014912D0; WO2000061305A3

Description

WO 00/61305 PCT/GBO0/01310 1 Apparatus and Method for determining the physical 2 condition of a pipeline 3 4 The present invention relates to a method and apparatus 5 for determining the physical condition of a pipeline. In 6 particular, the present invention relates to a pipeline 7 pig that can be used for such a purpose. 8 9 The incidence of damage to pipelines results in huge cost 10 to the oil industry in terms of lost production and 11 maintenance. The detection of defects or damage can be 12 done using a number of techniques, for example our co 13 pending Application 9812422.5 teaches the use of chemical 14 sensors to detect the occurrence and extent of corrosion. 15 This type of sensor is, however, not suitable for 16 detecting physical damage such as a dent or ovality. 17 18 Currently, the most favoured technique for detecting 19 physical damage is via the use of a pipeline pig on which 20 is mounted an aluminium disc. Typically, the disc is 21 formed from soft aluminium set to a diameter of 95% of 22 the minimum internal diameter of the pipeline. The discs 23 are usually several millimetres thick and may be WO 00/61305 PCT/GB00/01310 2 1 provided with a series of radial slits to give 2 approximately 6-8 "petals". When the pig is used in a 3 pipeline there are two possible outcomes: 4 5 1. The pig emerges from the pipeline undamaged, indicating 6 that the pipeline is undamaged; or 7 8 2. The pig emerges from the pipeline with its gauge plate 9 deformed, indicating that there has been damage to the 10 pipeline. 11 12 There are, however, a number of disadvantages with the 13 use of this type of pig. Firstly, to determine the 14 presence of any damage the pig has to be examined 15 visually which means that it must be recovered from the 16 pipeline. This is unsatisfactory if the pipeline is 17 subsea and several miles in length. 18 19 In addition, the pig is not provided with means for 20 relaying the precise location of any damage or defects in 21 the pipeline. 22 23 Furthermore, once the pig has passed one section of 24 damage and part of the plate has been displaced, the pig 25 may be unable to register the presence of any further 26 damage. 27 28 Damage to a pipeline can, alternatively, be detected by 29 physical inspection of the external surface by an 30 individual such as a diver. Again, however, the 31 dimensions and location of typical pipelines make this 32 method of damage detection unsatisfactory.

WO 00/61305 PCT/GBOO/01310 3 1 2 It would therefore be desirable to be able to use 3 apparatus that is able to detect the occurrence of 4 pipeline damage and send a signal indicating such to a 5 remote centre. 6 7 It would also be desirable for such apparatus to indicate 8 the location of any damage in the pipeline. This feature 9 would be particularly desirable where the pipeline is 10 several miles in length. 11 12 It is an object of the present invention to provide 13 apparatus that can be used to accurately detect the 14 presence of one or more pipeline defects, wherein the 15 apparatus does not have to be retrieved from the pipeline 16 or visually examined to detect said faults. 17 18 It is a further object of the present invention to 19 provide apparatus for detecting the condition of a 20 pipeline wherein the apparatus may be operated and 21 monitored from a remote location. 22 23 According to a first aspect of the present invention 24 there is provided apparatus for determining the physical 25 condition of a pipeline, wherein the apparatus comprises 26 a gauge plate mounted on a mobile carrier, the gauge 27 plate being provided with detection means for detecting 28 deformation of the gauge plate resultant from physical 29 defects in the pipeline, and the apparatus further 30 comprising transmission means to indicate to a remote 31 location the detection of the presence of physical 32 defects.

WO 00/61305 PCT/GBOO/01310 4 1 2 Optionally the detection means is a mechanical device. 3 4 Optionally the detection means is a strain gauge. 5 6 Alternatively the detection means is in the form of a 7 conductive element formed by an electrically or optically 8 conductive material. 9 10 Preferably the conductive element is applied to or 11 mounted on the rear face of the gauge plate. 12 13 Optionally the detection means is in the form of an 14 electrical circuit formed by tape such as fracture 15 detection tape or glass break tape. However, any 16 suitable tape may be used. 17 18 Where a tape is used as the detection means, the tape is 19 fixed to the plate such that a closed circuit is formed 20 while the plate remains undamaged and an open circuit is 21 formed when the plate becomes damaged. 22 23 The detection means communicates with the transmission 24 means when the gauge plate is deformed. The transmission 25 means is in the form of an acoustic, electromagnetic, 26 nucleonic or mechanical system, and transmits information 27 to a remote location. In addition, the apparatus may be 28 operated from said remote location. 29 30 The carrier may be, but is not limited to, a pipeline 31 pig. 32 WO 00/61305 PCT/GBO0/01310 5 1 Optionally the gauge plate is made from an elastomeric 2 material. 3 4 Preferably the plate is provided with a series of radial 5 slits which divide the plate into individual "petals". 6 7 Preferably the apparatua is propelled throught he 8 pipeline by pipeline fluid. 9 10 According to second aspect of the present invention there 11 is provided a method of determining the physical 12 condition of a pipeline comprising the steps of: 13 14 a) passing a carrier through the pipeline, the carrier 15 comprising a gauge plate and detection means for 16 detecting deformation of the gauge plate; and 17 b) transmitting a signal to a remote location upon said 18 detection by the detection means. 19 20 The data may also be stored on the carrier, and collected 21 and analysed once said carrier has passed through the 22 desired section of pipeline. 23 24 In order to provide a better understanding of the present 25 invention, an embodiment will now be described by way of 26 example only with reference to the accompanying Figures 27 in which: 28 29 Figure 1 illustrates a pipeline pig in 30 accordance with the present invention; 31 WO 00/61305 PCT/GBOO/01310 6 1 Figure 2 illustrates a view of a gauge plate 2 that can be mounted on a pipeline pig in 3 accordance with the present invention; and 4 5 Figure 3 illustrates the pipeline pig of Figure 6 1 in use in a pipeline. 7 8 Referring firstly to Figure 1 apparatus for determining 9 the condition of a pipeline is generally depicted at 1 10 comprising a carrier means 2, a gauge plate 3 and a 11 transmitter 4. The carrier means 2 is further provided 12 with supports 5. 13 14 Figure 2 illustrates a face view of the gauge plate 3. 15 The gauge plate 3 is provided with a central aperture 6 16 for connection with the transmitter 4 of Figure 1. In 17 addition the gauge plate 3 is provided with detection 18 means 7, slits 8 and a connector 9. The connector 9 19 provides a connection between the detection means 7 and 20 the transmitter 4. 21 22 In one embodiment the gauge plate 3 is made from an 23 elastomeric material. The gauge plate 3 will be deformed 24 upon passing a physical defect in the pipeline. However, 25 as the gauge plate 3 is made from an elastomeric 26 material, it will return to its original shape after 27 passing the physical defect. This is an advantage as the 28 apparatus 1 will not be detrimentally affected upon 29 passing a first defect in the pipeline and will therefore 30 be able to register the presence of other physical 31 defects further along the pipeline. 32 WO 00/61305 PCT/GBOO/01310 7 1 Figure 3 illustrates the apparatus 1 in use in a pipeline 2 10. In the Figure the apparatus 1 has passed a dent 11 3 in the wall of the pipeline 10. The gauge plate 3 has 4 been bent at point 12 by the action of the apparatus 1 5 passing the dent 11. The arrow indicates the direction 6 of movement of the apparatus 1 through the pipeline 10. 7 8 The apparatus 1 is inserted at one end of the pipeline 10 9 and propelled forwards, typically by the force of the 10 fluid travelling through the pipeline. The design of the 11 gauge plate 3 is such that the use of external propulsion 12 means has no detrimental effect on the detection means 7. 13 In one preferred embodiment the detection means is formed 14 by an electrically or optically conducting material. For 15 example, the detection means may comprise an electrical 16 circuit which is formed by tape 3, such as fracture 17 detection or glass break tape. The tape 4 forms a closed 18 circuit when the plate 3 is intact, the signal from this 19 circuit being transmitted to a remote centre from the 20 transmitter 4. However, when the apparatus 1 meets a 21 fault one or more of the slits in the gauge plate 3 bends 22 and results in the circuit being broken. The resultant 23 interruption or alteration of the signal can be monitored 24 by the remote centre and the location of the fault can be 25 accurately determined. 26 27 In a second preferred embodiment the detection means is 28 mechanical. For example, a strain gauge may be 29 incorporated into the gauge plate to detect physical 30 defects in the pipeline. 31 WO 00/61305 PCT/GBO0/01310 8 1 The apparatus may also be provided with data storage 2 means for recording information during a sweep through 3 the pipeline. The information so recorded can be 4 analysed once the sweep has been completed. This is 5 useful as a back up mechanism if for some reason 6 communication between the detection means and 7 transmission means or remote centre is interrupted or 8 detrimentally affected. As the apparatus has storage 9 means, any information gained during a sweep will not be 10 lost if the transmitting function of the pig is 11 detrimentally affected. It will be appreciated, that as 12 one sweep can take a considerable length of time, 13 particularly in long, subsea pipelines, this back-up 14 mechanism ensures that time and expenditure has not been 15 wasted on a run if the transmitting function of the 16 apparatus is affected. 17 18 The gauge plate may also be adapted to allow for the 19 measurement of subtle defects such as curvature of the 20 pipeline. 21 22 The transmitting means which transmits the information 23 regarding the physical condition of the pipeline to the 24 remote centre, may be in the form of an acoustic, 25 electro-magnetic, nucleonic or mechanical system, 26 depending on the prevalent conditions in the pipeline and 27 the operator's preference. 28 29 An advantage of the present invention is that the 30 pipeline pig can be inspected for damage without having 31 to visually examine it. Therefore the physical condition WO 00/61305 PCT/GBOO/01310 9 1 of the pipeline can be monitored without having to 2 retrieve the pig from the pipeline. 3 4 A further advantage is that there is provided apparatus 5 for detecting physical faults in a pipeline that can be 6 operated from a remote location. 7 8 A further advantage of the present invention is that any 9 faults that are detected can be repaired within a short 10 period of time and at considerably reduced cost. 11 12 A yet further advantage of the present invention is that 13 where the gauge plate is made from an elastomeric 14 material, the gauge plate will return to its original 15 shape after passing the defect in the pipeline and can 16 therefore be used to indicate other faults further along 17 the pipeline. The gauge plate may also be provided with a 18 feedback mechanism such that the gauge plate on passing a 19 fault can be reset to its original position allowing for 20 the measurement of a multiple of faults. 21 22 Further modifications and improvements may be added 23 without departing from the scope of the invention herein 24 intended.

Claims

1. Apparatus for determining the physical condition of a pipeline, wherein the apparatus comprises a gauge plate mounted on a mobile carrier, the gauge plate being provided with detection means for detecting deformation of the gauge plate resultant from physical defects in the pipeline, and the apparatus further comprising transmission means to indicate to a remote location the detection of the presence of physical defects.

2. Apparatus as claimed in Claim 1 wherein the mobile carrier is a pipeline pig.

3. Apparatus as claimed in any one of the preceding Claims wherein the detection means is a strain gauge.

4. Apparatus as claimed in any one of the preceding Claims wherein the detection means is in the form of a conductive element formed by an electrically or optically conductive material.

5. Apparatus as claimed in Claim 4 wherein the conductive element is applied to or mounted on the rear face of the gauge plate.

6. Apparatus as claimed in any one of the preceding Claims wherein the detection means is an electrical circuit formed by tape.

7. Apparatus as claimed in Claim 6 wherein the tape is fracture detection tape. WO 00/61305 PCT/GB0O/01310 11

8. Apparatus as claimed in Claim 6 wherein the tape is glass break tape.

9. Apparatus as claimed in any one of Claims 6 to 8 wherein the tape is fixed to the plate such that a closed circuit is formed while the plate remains undamaged and an open circuit is formed when the plate becomes damaged.

10. Apparatus as claimed in any one of the preceding Claims wherein the transmission means is an acoustic system.

11. Apparatus as claimed in any one of Claims 1 to 9 wherein the transmission means is an electromagnetic system.

12. Apparatus as claimed in any one of Claims 1 to 9 wherein the transmission means is a nucleonic system.

13. Apparatus as Claimed in any one of Claims 1 to 9 wherein the transmission means is a mechanical system.

14. Apparatus as claimed in any one of the preceding Claims wherein the gauge plate is provided with a series of radial slits which divide the plate.

15. Apparatus as claimed in any one of the preceding Claims wherein the guage plate is made from an elastomeric material. WO 00/61305 PCT/GBO0/01310 12

16. Apparatus as claimed in any one of the preceding Claims wherein the apparatus is propelled through the pipeline by pipeline fluid.

17. Apparatus as claimed in any one of the preceding Claims wherein the carrier is adapted to store data.

18. A method of determining the physical condition of a pipeline comprising the steps of: a) passing a carrier through the pipeline, the carrier comprising a gauge plate and detection means for detecting deformation of the gauge plate; and b) transmitting a signal to a remote location upon said detection by the detection means.