Method and device for indspecting pipelines

• US 20030136195A1
• Filed: 03/15/2002
• Published: 07/24/2003
• Est. Priority Date: 01/22/2002
• Status: Active Grant

• Current Assignee: PII Pipetronix GmbH (Baker Hughes Company)
• Original Assignee: PII Pipetronix GmbH (Baker Hughes Company)
• Inventors: Krieg, Wolfgang, Hugger, Achim
• Granted Patent: US 6,848,313 B2
• Time in Patent Office: Days
• US Class Current: 73/628
• CPC Class Codes: G01N 2291/0235 Plastics; polymers; soft materials, e.g. rubber
• CPC Class Codes: G01N 2291/0421 Longitudinal waves
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/106 one or more transducer arrays
• CPC Class Codes: G01N 2291/2636 cylindrical from inside
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/2456 Focusing probes focusing arrangements G01N29/221
• CPC Class Codes: G01N 29/262 by electronic orientation or focusing, e.g. with phased arrays phased arrays per se G10K11/34
• CPC Class Codes: G01N 29/341 with time characteristics

Abstract

The invention concerns a method and a device for inspecting pipelines, in particular for detecting defects in pipelines by means of ultrasound. Towards this end, measuring sensors transmit ultrasound signals during passage through a pipeline. The signals reflected on boundary regions of a pipeline wall, e.g. surfaces or defects, are then measured and evaluated. The invention is characterized in that partial regions of the measuring sensors (virtual sensors) formed of a plurality of neighboring sensor elements irradiate ultrasound signals into the pipe wall at at least one radiation angle which is inclined with respect to the normal to the pipe wall and the signals reflected at boundary regions of the pipe wall are received by same and/or other partial regions of the respective measuring sensors, wherein defects in the pipe wall are determined by evaluation of the acoustical signals reflected by different boundary regions.

Claims

1. A method for inspecting the pipe wall of a pipeline for defects, the method comprising the steps of:

a) introducing a plurality of measuring sensors into the pipeline, each measuring sensor comprising an array of controllable sensor elements;

b) defining a plurality of virtual sensors, each virtual sensor comprising an array of neighboring sensor elements;

c) controlling at least a portion of said virtual sensors to irradiate ultrasound signals into said pipe wall at at least one irradiation angle which is inclined relative to a normal to the pipe wall;

d) receiving ultrasound signals reflected by bordering surfaces of the pipe wall in at least a portion of said virtual sensors; and

e) evaluating said received signals from differing bordering surfaces to determine pipe wall defects.

2. The method of claim 1, wherein sensor elements of said virtual sensors are controlled with a relative mutual signal irradiation delay.

3. The method of claim 2, wherein a signal radiation distance between the pipe wall said measuring sensors is kept substantially constant during steps c) and d).

4. The method of claim 2, wherein said inclined irradiation angle of said irradiated ultrasound signals with respect to said normal to the pipe wall is selected such that the acoustical wave propagates, after refraction at a boundary region between the pipe inner space and pipe wall, at an angle of approximately 45°

with respect to said normal to the pipe wall.

5. The method of claim 1, further comprising irradiating a signal at a second angle which is a mirror image of said inclined irradiation angle with respect to said normal to the pipe wall.

6. The method of claim 1, wherein step c) comprises the steps of sequentially actuating different virtual sensors of said measuring sensors in a repeating fashion to displace radiating virtual sensors of said measuring sensor in time along said measuring sensor until all sensor elements of each individual measuring sensor have been actuated at least once.

7. The method of claim 6, wherein each virtual sensor comprises a same number of sensor elements.

8. The method of claim 6, wherein regions of the pipe wall are irradiated from at least two directions.

9. The method of claim 1, wherein an overall radiation of all virtual sensors of all measuring sensors produces a complete signal coverage of the pipe wall in a peripheral direction.

10. The method of claim 9, wherein said complete signal coverage of the pipe wall in said peripheral direction results from a fixed geometrical arrangement of said measuring sensors.

11. The method of claim 9, further comprising rotating said measuring sensors to produce said complete signal coverage of the pipe wall in said peripheral direction of the pipeline.

12. A device for inspecting the pipe wall of a pipeline for defects, the device comprising:

means for introducing a plurality of measuring sensors into the pipeline, each measuring sensor comprising an array of controllable sensor elements;

means for defining a plurality of virtual sensors, each virtual sensor comprising an array of neighboring sensor elements;

means for controlling at least a portion of said virtual sensors to irradiate ultrasound signals into said pipe wall at at least one irradiation angle which is inclined relative to a normal to the pipe wall;

means for receiving ultrasound signals reflected by bordering surfaces of the pipe wall in at least a portion of said virtual sensors; and

means for evaluating said received signals from differing bordering surfaces to determine pipe wall defects.

13. The device of claim 12, further comprising at least one sensor support having said measuring sensors disposed substantially circularly around said sensor support, wherein each of said sensor elements can be individually controlled.

14. The device of claim 13, further comprising at least one resilient sensor suspension for each measuring sensor to urge said measuring sensors towards an inner wall of the pipeline.

15. The device of claim 13, wherein said sensor elements of a measuring sensor are disposed in a shape of a linear array.

16. The device of claim 13, wherein said measuring sensors have a curvature along an extension in a peripheral direction which is adapted to a curvature of the pipe wall.

17. The device of claim 13, wherein a plurality of measuring sensors is disposed as a group at a common axial position, wherein said plurality of measuring sensors have mutual separations in a peripheral direction.

18. The device of claim 17, wherein sensor elements of one group of measuring sensors are disposed on a circle which is concentric to an inner periphery of the pipe wall.

19. The device of claim 18, wherein said measuring sensors can be rotated in said peripheral direction along a circle which is concentric to an inner periphery of the pipe wall.

20. The device of claim 17, wherein a plurality of groups of measuring sensors are offset with respect to each other in an axial direction and in said peripheral direction, wherein said measuring sensors partially overlap in said peripheral direction.

21. The device of claim 12, wherein said controlling means trigger temporally offset control of individual sensor elements of said measuring sensors to change at least one of a direction of propagation and a focusing depth of a measurement pulse in at least one of said peripheral direction and a radial direction.

22. The device of claim 13, wherein said sensor support has at least one central circular cylindrical element disposed coaxially to said measuring sensors for mounting thereof.

23. The device of claim 13, further comprising a guiding disc disposed concentrically with respect to a longitudinal axis, said guiding disc being flexible at least in an edge region thereof and having a circular cross-section whose largest diameter is at least as large as an inner diameter of the pipeline.

24. The device of claim 23, wherein said guiding disc comprises one of a plastic material and polyurethane.

25. The device of claim 13, wherein said sensor support comprises, for each measuring sensor, at least two articulated arms which are hinge connected to each other and whose free end is hinge connected to one of a mounting element of a sensor rocker receiving said measuring sensor and to a central element of said sensor support.

27. The device of claim 25, wherein one of said at least two articulated arms is hinged to said central element to form a first telescopic spring element.

28. The device of claim 27, further comprising a second telescopic spring element disposed between said sensor rocker and elements of a sensor suspension.

29. The device of claim 25, wherein said sensor rockers are formed such that a curvature in a peripheral direction of surfaces thereof facing the pipe wall substantially corresponds to a curvature of said measuring sensors.

30. The device of claim 29, wherein said measuring sensors are fitted into a groove in an upper surface of said sensor rockers extending in a peripheral direction, wherein a depth of said groove corresponds substantially to a radial dimension of said measuring sensors.

31. The device of claim 30, wherein said sensor rockers have an axial length which exceeds that of said measuring sensors.

32. The device of claim 31, further comprising spacers disposed on said sensor rockers at a region of said excess axial length.

33. The device of claim 32, wherein said spacers have a wear protection at upper sides thereof facing the pipe wall.

26. The device of 25, wherein said hinge connections are hinge joints.