NDT3D IWEX A novel ultrasonic testing method for improved defect detection, identification, and sizing - World Pipelines Magazine
02/08/2017
Detection, identification and sizing of defects in both in-service and new construction piping are essential for any quality or integrity management programme.
Non destructive testing (NDT) techniques are used to identify issues relating to the manufacture of pipe, in-service flaw formation and degradation, and weld joints that are created during pipeline construction. Each application has unique challenges but the pipe vintage, manufacturing process, welding technique, defect orientation and human effects can impact proper data collection and interpretation.
After years of development, Applus+ RTD introduced Inverse Wavefield Extrapolation (IWEX), also known as NDT3D IWEX, as a novel ultrasonic testing (UT) method. This method has been designed to improve defect detection, identification and sizing.
IWEX refers to a methodology that constructs images from measurements using ultrasonic waves. The output from the NDT3D IWEX can be compared to medical ultrasound technology during pregnancy and seismic imaging used in oil and gas exploration. Data recorded by ultrasonic arrays is processed using the same imaging technique. The result is an actual image of the inspected volume, rather than a plot of the collected signals. The technology can discriminate closely spaced defects and accurately size cracks irrespective of their orientation.
A key advantage of the Applus+ RTD IWEX technology is that the inspection result is presented in a comprehensive and intuitive 2D and 3D image that illustrates flaws. Therefore, properties such as location, orientation and size can be determined accurately. The processing speed of IWEX imaging allows for real time viewing of the 3D images and can be rotated and zoomed to assist with identification. Figure 1 demonstrates how acquired data are processed by the IWEX algorithm into 2D and 3D images to provide improvements to both flaw sizing and orientation.
A significant portion of the global energy pipeline infrastructure is constructed with pipe materials manufactured using the electric resistance welded (ERW) process. The longitudinal seam of these pipelines may contain manufacturing flaws that can degrade in service and result in a pipeline failure. Pipeline operators need the ability to separate flaws that can degrade from those in the longitudinal seams that are stable and, generally, pose no threat to pipeline integrity. These types of manufacturing flaws are challenging to detecting, identifying and sizing using current inline inspection (ILI) and in-ditch technologies, which is driving the industry to better understand current inspection performance and develop new technologies for seam anomaly inspections.
In summary, Applus+ RTD’s IWEX technology is an emerging platform that can be utilised for many different applications. New industry and customer-driven development projects are underway in several markets including oil and gas.
Figure 1. A weld defect.