Four crude pipelines were recently constructed as part of Saudi Aramco pipelines rehabilitation projects. The pipelines transfer stabilized sweet crude from a crude processing facility to exporting terminals.

Baseline in-line inspection (ILI) runs were conducted after one year of the commissioning. The ILI indicated internal corrosion findings in all pipelines where the metal loss mostly varied from 21% to 40%. However, more severe findings were observed in one of the pipelines where the internal corrosion reached more than 70% metal loss. Field verification was carried out at several locations using Automated Ultrasonic Corrosion Mapping and confirmed a maximum thinning of 71%.

This paper provides a comprehensive investigation aiming to reveal all contributing factors. The investigation approach followed the diagnosis of exclusion process by reviewing the full pipelines’ lifecycle including the design, materials procurement, construction, pre-commissioning and operation phases. The investigation revealed several factors that believed to have a contribution to these high metal loss findings. Lessons learned from this investigation were captured as potential enhancements to the relevant company’s standards and procedures.