SHEAR-WAVE ULTRASONIC CRACK INSPECTION TOOL PERFORMANCE FOR CRACKS ASSOCIATED WITH METAL LOSS

摘要

Shear-wave ultrasonic in-line tools are used for crack management in liquids pipelines. An ultrasonic pulse is generated, travels in the pipe wall and reflects on axially oriented artifacts that could be geometric or cracklike in nature. If several geometrical artifacts are present, detection and sizing efficiency of these ultrasonic inspection tools could be reduced. Cracking located within corrosion is one possible interacting set of geometrical artifacts that could affect in-line inspection (ILI) performance. As part of continuous improvement, a comprehensive review of two thousand three hundred and thirty eight in-the-ditch measurements of cracking in corrosion were compared to crack ILI reported features in order to determine the tool performance in cases where cracks were associated with metal loss. Relationships of depth and predicted burst pressures were reviewed and compared to cracks not associated with metal loss. Additionally, field NDE results that had incomplete information in the ILI-NDE correlation files with indications of being potential defects were reviewed to examine the possibility of undocumented coincident cracking in metal loss that could represent an integrity threat. This paper summarizes the results and potential implications for management of cracking in corrosion using shear-wave ultrasonic crack ILI.