Comparative study of assessment methods to predict the hydrostatic collapse of subsea pipelines with interacting corrosion defects

Resumo

Assessing corroded subsea pipelines' structural integrity and risk management is a current challenge for the offshore industry. Corrosion defects are commonly distributed randomly along the subsea pipeline, leading to interactions between neighboring defects. Interacting corrosion defects play an important role in the evaluation of the collapse response of these pipes. So, this paper investigates the hydrostatic collapse of subsea pipelines with interacting corrosion defects through numerical analyses based on finite element models. The PIPEFLAW system, developed by the PADMEC (High-Performance Processing in Computational Mechanics) research group at UFPE (Federal University of Pernambuco), is used to generate the 3D FE models and perform nonlinear analyses automatically. The analyses include subsea pipelines with dual and multiple corrosion defect configurations. A parametric study is carried out to compare the collapse prediction and different semi-empirical methods available in the literature. Additionally, a novel approach introduced in recent research is evaluated. This approach subdivides the corrosion zone into sub-defects with an equivalent length, width, and depth. The findings demonstrate that this methodology performs better than traditional evaluation methods for predicting the collapse pressure of subsea pipelines with interacting corrosion defects. Thus, the novel approach contributes to more accurate and less conservative assessments and may become a practical tool for the integrity assessment of corroded pipelines in offshore environments.