Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Collapse of subsea pipelines: Numerical study on the interaction of corrosion defects with different geometric properties
Submission Author:
Savanna Cristina Medeiros D'Aguiar , PE , Brazil
Co-Authors:
Savanna Cristina Medeiros D'Aguiar, Silvana Maria Bastos Afonso da Silva, RENATO MOTTA
Presenter: Savanna Cristina Medeiros D'Aguiar
doi://10.26678/ABCM.COBEM2023.COB2023-1669
Abstract
Subsea pipeline integrity and risk management is a constant challenge due to the hostile environment and operational conditions changes. These pipelines are usually subjected to corrosion attacks. The corrosion geometry is random and can be modeled as a single defect or a group of defects. Multiple corrosion defects can interact with each other and significantly affect the resistance capacity of corroded pipelines. The spacing between defects plays an important role, as when it increases, the interaction between defects decreases. However, the interaction rules also depend on the mutual orientation of the defects, their geometry, and other parameters. The Finite Element (FE) Method has been widely used to evaluate the residual strength of corroded pipelines. Numerical FE analyses present efficient and reliable results and allow extensive parametric studies. This paper evaluates the influence of the spacing between corrosion defects with different sizes on the resistance to the collapse of subsea pipelines under high external pressure. Nonlinear analyzes will be performed using the PIPEFLAW system, developed by the PADMEC (High-Performance Processing in Computational Mechanics) research group from UFPE (Federal University of Pernambuco). The PIPEFLAW integrates various tools for automatic FE model generation and FE analysis. The generated FE models were validated against experimental results available in the literature, and a good agreement was reached. After validation, sensitivity studies are conducted on interaction mechanisms for various parameters, considering dual defects with different geometrical properties positioned longitudinally. In general, it is found that the size of the defect has the most significant influence on the interaction between defects. Other factors, such as pipe characteristics and initial ovality, are essential in defect interaction rules. Thus, the results obtained in this study can contribute to advancing knowledge about the effects of interactive defects of different sizes on the collapse resistance of subsea pipelines.
Keywords
Subsea Pipelines, collapse pressure, corrosion, Defect Interaction Rules, Numerical simulation
