Ultrasonic immersion testing for crack detection in large diameter pipes

Speaker:
Rachev, Rosen; University of Bristol; United Kingdom

Authors:
Rachev, R.; University of Bristol; United Kingdom
Wilcox, P.; University of Bristol; United Kingdom
Velichko, A.; University of Bristol; United Kingdom
McAughey, K.; Baker Hughes, a GE Company; United Kingdom
Giese, J.; Baker Hughes, a GE Company; United Kingdom

ID: ECNDT-0084-2018
Download: PDF
Session: Applied PAUT 1
Room: G2
Date: 2018-06-14
Time: 13:30 - 13:50

Detection and sizing of surface breaking defects in pipelines is of vital importance in the petrochemical industry. The work presented focuses on in-service inspections of large diameter (above 24″) pipes with ultrasonic phased arrays. Experimental data is obtained from scans in immersion from the inside of the pipe with emphasis on detection and depth sizing of axial cracks. The depth measurements are extracted from images produced using advanced signal processing algorithms such as TFM and PWI. The proposed sizing technique is to be applicable on oil pigs performing in-line inspections (ILI). Pigs inspect hundreds of kilometres of pipelines moving at high velocities resulting in limited acquisition time at a specific location. The image-based sizing from PWI with a single transmission is demonstrated comparable to these of TFM and PWI with multiple transmissions, suggesting the approach is an applicable ILI alternative. The work quantifies the depth sizing performance of the technique with respect to parameters such as defect position, aperture size and inspection angle.