Damage Assessment of Pipelines With Dents and Cracks: Proposal for Methodology for Calculation of Acceptable Dimensions of a Combination of Crack and Dent in Subsea Pipelines

This paper presents a proposal for methodology to evaluate the maximum acceptable combination of longitudinal crack and dent in an offshore pipeline. The procedure is based on 2-parameter fracture mechanics FE analyses and fatigue calculations. The reduction in material capacity due to the dent damage is modeled by increasing the driving force by introducing a stress concentration factor to the load. The framework presented in this article represents one possible approach for determining whether a given measured damage to a pipeline must be repaired or if it is sufficient to monitor the damage in the future. Avoiding unnecessary repairs of damaged but viable subsea pipelines is a substantial cost-saving issue.