A novel practical approach to cool down time thermal analyses in the oil and gas field

Abstract

This paper introduces an innovative 'iterative-FEA' (iFEA) approach aimed at maintaining the accuracy of subsea production system (SPS) cool-down simulations, typical for CFD, while significantly reducing computation time to a level akin to FEA modeling. To assess this method's effectiveness, flow system test cases were modeled using both CFD and iFEA methods. The models were validated applying a full-scale experimental rig, incorporating a dummy SPS section immersed in a water container and equipped with a comprehensive data measurement and acquisition system. The rig simulated the system's operation and underwent experimental testing using three distinct working fluids: water, air, and diesel oil. A very good agreement can be observed when comparing the computational results with the experiments. The maximum error for CFD is 2.52°C, whereas for iFEA it is 2.7°C. The average simulation time for the iFEA models was over 10 times shorter than that of the full CFD simulation, despite the substantially lower computational power of the cluster. This achievement represents a breakthrough in industrial SPS thermal simulations.