Fatigue Reliability Analysis For Deepwater Drilling Riser System

To make sure the safety and success of deepwater drilling, deepwater drilling riser system fatigue safety analysis is necessary. The paper is focused on the fatigue reliability assessment on deepwater drilling riser system, with support of"863"project : deepwater drilling and completion-- deepwater riser and wellhead technology.This paper presents a finite model of the deepwater drilling riser, based on spectrum analysis method in frequency domain, a method for solving the wave induced fatigue load spectrum of deepwater drilling riser is described. Deepwater drilling riser fatigue reliability under the random wave loading is investigated, and the parameter sensitivity analysis of all factors affecting wave induced fatigue reliability is done. Based on mode superposition and finited element simulation, a method to consider the total stress parameter of Vortex-induced Vibration fatigue loading is proposed. The effects of flow parameters and structure parameters on deepwater drilling riser VIV fatigue reliability are assessed, for the purpose of supplying references to the deepwater drilling operation. A three-dimensional finite element model for the riser coupling is established, and based on the international universal standards, an evaluation method of riser coupling FEM (finite element method) calculation results is suggested, for the purpose of supplying references to the type selection of riser coupling. On the premise of FEM calculation results, the fatigue reliability analysis of riser coupling is performed. At last, based on the dynamic wave loading analysis of the riser system in time domain, system fatigue reliability of riser is evaluated. The research on the fatigue reliability optimization of deepwater drilling riser system would be used to provide references to the deepwater drilling operation.