Mechanical Analysis of the Wave-Induced Fatigue in the Subsea Wellhead

Based on the actual working conditions of subsea drilling jobs, the subsea wellhead and riser system, mechanical and finite element 3D model are established to further analyze the system. Then, the AQUA mode of the ABAQUS is used to simulate the wave and ocean current loads. And RAO of the platform is used to obtain the transfer function between the wave loads and the wellhead fatigue hot spots. Then the wave scatter map is combined with the S-N curve to calculate the wave-induced fatigue life in the subsea wellhead. The analysis of the example shows that the fatigue life of sub-sea wellhead can meet the requirements of the DNVGL specifications.