The Influence of Slug Characteristics on Oscillation of Steel Catenary Risers in the Non-Linear Hysteretic Seabed

Xiaoyu Dong, Hodjat Shiri

In the proceedings of GeoSt. John's 2019: 72nd Canadian Geotechnical Conference

Session: Offshore and Nearshore

ABSTRACT: Steel catenary risers (SCR) are widely used in the development of offshore fields and are exposed to severe fatigue loads generated by environmental and operation loads. Slugging can induce SCR oscillations in the touchdown zone (TDZ) and cause the cyclic degradation of seabed soil. In this study, the influence of slug characteristics on SCR oscillation in the TDZ was comprehensively investigated by developing numerical models in ABAQUS with FORTRAN interfaces. The slugging characteristics such as density, length, velocity etc. have been examined together with the influence of non-linear hysteretic riser-seabed interaction, and complex vessel excitations. The study revealed several important trends of SCR response to slug-induced oscillations in the non-linear hysteretic seabed and consequently on accumulated fatigue damage in the TDZ.

RÉSUMÉ: Les colonnes montantes de caténaires en acier (SCR) sont largement utilisées dans le développement de champs offshore et sont exposées à des charges de fatigue sévères générées par des charges environnementales et opérationnelles. Les slugging peuvent induire des oscillations de RCS dans la zone de toucher des roues (TDZ) et ristiques des le TDZ a été largement étudiée en développant des modèles numériques dans ABAQUS avec des interfaces FORTRAN. Les caractéristiques de slugging telles que la densité, la longueur, la vitesse, etc. ont on linéaire hystérétique entre le riser et le fond marin et les excitations complexes des navires. L'étude a révélé plusieurs tendances importantes en matière de réponse SCR aux oscillations induites par les bouchons dans le fond marin hystérétique non linéaire et, par conséquent, aux dommages de fatigue accumulés dans le TDZ.

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Cite this article:
Xiaoyu Dong; Hodjat Shiri (2019) The Influence of Slug Characteristics on Oscillation of Steel Catenary Risers in the Non-Linear Hysteretic Seabed in GEO2019. Ottawa, Ontario: Canadian Geotechnical Society.

@article{Geo2019Paper190,author = Xiaoyu Dong; Hodjat Shiri,title = The Influence of Slug Characteristics on Oscillation of Steel Catenary Risers in the Non-Linear Hysteretic Seabed,year = 2019}