Session: 08-07-01 Internal Flows & Fluid–Structure Interaction in Riser and Pipeline Systems

Submission Number: 180639

Fluid-Structure Interaction Analysis of Steel Catenary and Steel Lazy Wave Risers Under Slug Flow Conditions 

The steel catenary riser (SCR) and steel lazy wave riser (SLWR) represent two of the most commonly adopted configurations for deep water offshore production systems. Despite their specific structural advantages, both configurations are subject to complex dynamic interactions driven by internal flow and environmental loading, of which can significantly affect their dynamic response and, consequently, the input to fatigue assessment. In this context, this work presents a comparative analysis of the dynamic response of catenary and steel lazy wave risers subjected to slug flow conditions, while single-phase internal flow conditions are used for model validation and for establishing static and quasi-static baselines. The structural behavior of the risers is modeled using a nonlinear finite element formulation capable of capturing large elastic displacements. The internal flow model is therefore used to generate hydrodynamic load distributions that act as external excitation in the structural solver, in a one–way coupling sense.  The numerical implementation enables the evaluation of riser response at multiple critical nodes, providing a detailed understanding of displacement evolution over time and along the riser length. Model validation is performed through comparison with published results in the literature and numerical simulations performed in OrcaFlex, demonstrating the accuracy and robustness of the proposed methodology.   The results underscore the pronounced influence of internal flow regimes on riser dynamics and demonstrate that structural configuration modulates the system sensitivity to slug-induced excitation. In particular, variations in slug velocity and length primarily induce frequency shifts accompanied by non-monotonic amplitude responses, indicating that both parameters must be jointly considered when assessing internal-flow-induced riser dynamics.

Presenting Author: Igor Fortuna Lima Da Silva Federal University of Rio de Janeiro

Presenting Author Biography: PhD candidate in Nuclear Engineering at the Federal University of Rio de Janeiro (UFRJ), focusing on the thermohydraulic analysis of offshore nuclear reactors. Masters degree in Mechanical Engineering from the same institution, with an emphasis on nonlinear mechanics, chaotic systems, and applied artificial intelligence. Dual bachelor's degrees in Mechanical Engineering (2019) and Petroleum Engineering (2017) from the Catholic University of Petrópolis. Experienced researcher in the fields of nuclear, mechanical, and petroleum engineering, currently serving as a technical project manager for the development of high-performance software for riser dynamic simulation. Professional experience includes working in telecommunications at Orange Business Service as a Local Delivery Manager for North America and in the hydropower sector, developing intelligent systems for cavitation identification and classification in hydraulic turbines at MDM Sistemas. Practical experience in mechanical engineering and maintenance at the Angra dos Reis Nuclear Power Plant (Eletronuclear) and in projects in the oil and gas sector.

Authors:

Igor Fortuna Lima Da Silva Federal University of Rio de Janeiro
Luan Bastos Leal Azevedo Dos Reis Federal University of Rio de Janeiro
Carlos Eduardo Da Silva Federal University of Rio de Janeiro
Leandro Carlos Gazoni Federal University of Rio de Janeiro
José Luis Drummond Alves Federal University of Rio de Janeiro
Jian Su Federal University of Rio de Janeiro