Riser Modeling Scheme for a Load-Sharing Marine Drilling Riser

Typical riser analysis for a marine drilling riser using the conventional composite modeling scheme will have only one line of elements mathematically representing riser pipe and auxiliary lines. The mass and weight of the riser system may be properly modeled. It is up to the analyst to include auxiliary lines’ stiffness, bending and/or axial. The rule of thumb is to ignore them if the riser is not of load-sharing design, otherwise include them. However, even with stiffness included in the model, the composite modeling scheme will not capture the load path correctly. Parametric studies were performed to develop a modeling scheme for a load-sharing marine drilling riser. This paper compares the results by the newly developed modeling scheme with the composite model. Significantly different tension patterns between the two models are observed.