Improved axial dynamic analysis of risers based on finite element method and data-driven models

Axial dynamics of risers is one of challenges in offshore oil and gas engineering. Axial hydrodynamic loads on a riser system are often ignored in traditional analysis methods. To accurately analyze the axial dynamic response of risers, an improved axial dynamic analysis method of risers is proposed based on finite element method and data-driven models. Finite element method is introduced to analyze the structural response of risers while data-driven models are trained for the calculation of hydrodynamic loads through BP neural network. Finally, a comprehensive analysis algorithm is proposed for the axial dynamic analysis of risers by combining finite element method and data-driven models. The proposed method is demonstrated by its application to a case. It turns out that the hydrodynamic loads on key components have an obvious influence on axial dynamics of risers, especially the lower marine riser package (LMRP). The vibration amplitude of risers increases obviously and the vibration phase of risers presents a little lag with consideration of hydrodynamic loads. The detailed influence of hydrodynamic loads on axial dynamics of risers under different amplitudes and periods of platform motion and riser configurations is also studied based on the proposed method.