Cosimulation of a direct-acting riser-tensioner system-validation with field measurements and sample simulations

In this paper, the cosimulation methodology, presented in earlier works by the authors, is extended to full scale riser-tensioner system, with the semi-submersible platform and the riser stack being modelled in the ocean engineering software, OrcaFlex, and the hydro-pneumatic tensioner being modelled in the multiphysics software, SimulationX. An interface file coded in Python is used to couple the two models to run the cosimulation. Field measurements from an on-board data acquisition system, mounted on an operational semi-submersible drilling platform, is used to benchmark model performance. The motion time-history the platform, available in the field data, is used to specify heave motions of the model platform. A planned disconnect sequence is simulated, and the results are compared with field measurements. Subsequently, sample simulations are presented to demonstrate the possibilities of the proposed co-simulation methodology, including a simulation of the whole disconnect procedure, covering the connected, pull-off, disconnected, and soft hang-off phases of the system.

Automated summary

In this paper, the authors extend the cosimulation methodology to a full scale riser-tensioner system, using OrcaFlex to model the semi-submersible platform and the riser stack, and SimulationX to model the hydro-pneumatic tensioner. The two models are coupled using a Python interface file. Field measurements from an operational semi-submersible drilling platform are used to validate the model. A planned disconnect sequence is simulated and compared with field measurements. Sample simulations are also presented to demonstrate the capabilities of the proposed co-simulation methodology.