An Overview of Risk-Based Inspection Planning for Flexible Pipeline

There are many failure mechanisms that may occur in flexible pipes during their service life, such as external sheath damage, damage of tensile armours due to fatigue, kinks due to corrosion, and over-bending. The above mentioned defects are very common and can lead to the failure of flexible pipes. Therefore, huge operational costs have to be spent to ensure the integrity of the flexible pipeline system. Risk-Based inspection (RBI) methodology can establish a cost-effective strategy for inspection and monitoring, while maintaining the expected level of safety. However, there are some factors that can hamper the development of an optimized RBI for the integrity management of flexible pipelines, such as the complexity and variety of flexible pipes' multi-layer structures with their interacting failure mechanisms, the somewhat poor defect capability of the existing inspection techniques and the lack of broad [1]. In this paper, RBI planning is described thoroughly to ensure the integrity management of flexible pipelines. All risk terms have been described in detail with respect to integrity management strategy. The working process of RBI, including initial assessment and detailed assessment, is introduced. Estimation and evaluation of risk level, including the development of optimized inspection planning, have been described completely.