Shielded corrosion, particularly at girth weld areas, poses a significant threat to aged pipeline systems. Despite its widespread impact on many pipeline operators and numerous attempts to model its behavior, this damage mechanism remains largely unpredictable in terms of future attack locations and corrosion growth rate at affected locations, complicating the balance between risk management and mitigation expenditure.
This paper proposes a novel ALARP (As Low As Reasonably Practicable) approach to manage shielded corrosion. The methodology, applicable to both piggable and non-piggable pipelines, integrates innovative analytical processes with improved contracting and coating rehabilitation strategies to achieve up to 70% savings compared to previous strategy, while maintaining the risk of failure under the acceptance criteria.
The approach begins identifying and prioritizing affected locations through innovative analysis on data typically available to operators, delivering a tailored cost-efficient coating rehabilitation program. This program is frequently updated, based on field feedback, to ensure compliance with the company’s risk acceptance criteria until next scheduled integrity assessment.