determined that the production flowlines would be 20% hotter than the initial design considered. The objective was to determine if the umbilicals would exceed their maximum allowable temperature.


6.2 Summary of Simulation Model and Loading


This simulation was conducted in ABAQUS because of its cavity radiation functionality. The simulation was a simple, 2D, steady state heat transfer analysis. The air between the flowlines and umbilical was modeled only with conductive heat transfer. A thermal contact model was used to provide for heat transfer from the flowlines to the air gap.


6.3 Results


Contours of the radiation flux from the production flowlines are shown in Figure 15. These contours pass the reality check; considerably more radiation heat flux occurs between the cold outer shell of the riser turret and the hot production flowlines than is seen between those flowlines and the warmer umbilicals. The variation of the umbilical surface temperatures are shown in Figure 16. There is a very large temperature gradient around the surfaces of the umbilicals. This simulation predicts that the umbilical surface temperatures could exceed 85 o C. The umbilical engineering team and the flow assurance team will utilize this data to determine if forced convective cooling needs to be retrofitted to the riser turret design.


Such a change in thermal management methodology would be a strong driver to create an FSI model for this deepwater design challenge.


Figure 14. Temperatures assigned to the (4) production flowlines and the gas export line in the riser turret model.


2009 SIMULIA Customer Conference 15


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