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

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.