Dynamic characteristic analysis on deepwater drilling platform/tensioner/riser coupling system

Key words:  drilling riser  tensioner system  coupling dynamics  static analysis  dynamic analysis

Abstract:

To accurately predict the dynamic response of the riser system, and solve the problem where the boundary conditions are oversimplified in the traditional analysis method, a coupling dynamic model of deepwater drilling platform/tensioner/riser was established. Nonlinear stiffness variation of the tensioner system, as well as the multi-body coupling connection among the platform, the tensioner and the riser were fully considered in this new model. The static and dynamic response characteristics of the riser system were studied in the coupling system, and the coupling interaction manner of the drilling platform/tensioner/riser was revealed. The results show that,in the static analysis, the tensioner system provides a lateral force, which can suppress the offset and minimize the bending moment of the riser system. In the dynamic analysis, the tensioner system can significantly damp the transmission of the platform heave movement. When the drilling platform is in the pitch movement, the tensioner system has a great effect on the offset position of the riser system and has little effect on the motion amplitude of the riser. Compared with the traditional analysis model, the coupling dynamic model can apply the boundary condition precisely, and can accurately predict the dynamic response of the riser system.