SCC Detection and Coating Disbondment Detection Improvements Using the High Resolution EMAT ILI-Technology

Pipeline deterioration by stress corrosion cracking (SCC) is an increasing challenge for the pipeline industry. Recent incidents and the lately issued OPS advisory bulletin in the U.S., emphasize the worldwide focus on this phenomenon. Coating disbondment is understood as a precursor to SCC by increasing the susceptibility of the pipeline for corrosion. The presented High Resolution ILI-technology, based on a novel concept of an Electromagnetic Acoustic Transducer (EMAT), allows both, the detection of SCC and the detection of disbonded coating, using two independent measurement methods. Thus, the technology combines proactive and reactive measures to improve the reliability of a pipeline that is susceptible to SCC. Data from a series of full-scale tests, obtained with the ILI-EMAT prototype, will be presented. The tests were conducted on pipe containing natural SCC colonies. The improvement of SCC detection capability will be demonstrated.