A Framework for Managing the Threat of SCC and Other Forms of Cracking in Pipelines Using In-Line Inspection Tools

The phenomenon of Stress Corrosion Cracking (SCC) as a major integrity threat has been investigated intensively and discussed since the 1970’s. Based on the far-reaching understanding of this threat today, integrity management programs have been developed further in recent past. A framework approach is proposed of dividing the integrity management into a process-based structure. Within this structure the different processes from the inspection program to the control of the immediate and future integrity are arranged in a closed loop. The framework has been applied to a Williams 26-inch gas pipeline. The pipeline has been inspected with a high resolution in-line inspection tool, using electromagnetic acoustic technology (EMATs), with a sensitivity to coating disbondment and SCC, proven by detailed results obtained from pipe samples containing SCC. In preparation of an extensive in-field evaluation program, an engineering critical assessment and a risk based analysis of limit conditions are conducted. The results from the in-field program are used to support the subsequent process of tool performance validation and integrity control.