Subsea diver-less connections in general are not subjected to fatigue load. By principle, they don't require a fatigue analysis, however, due to some uncertainties in field like slugging causes damage to these structures. Since these structures are not designed for fatigue, it is important to check its resistance and understand remaining strength when such phenomenon happens. The paper discusses about estimating the fatigue damage due to slugging phenomena which is a high frequency phenomena using combination of finite element and analytical solution. The loading action on the structure could be combination of axial force, transverse force and bending moment. The remaining fatigue life can then be estimated based on Miners rule. The paper also discusses about the probabilistic approach where variations in loading, material curve and Miners limit is considered to qualitatively understand safety of system for remaining service. For probabilistic analysis, reliability tools like Weibull analysis is used to assess the change in reliability of component and hence establish the relative damage in structure. Based on linear extrapolation of accumulated damage, using Miner rule based on DNV RP C203, the remaining life was estimated to be 9.69 years compared to 40 years of design life. However, the probabilistic approach is adopted to showcase that the slugging has lowered the reliability for fatigue failure of the critical component has dropped by less 20% for 9.69 years. The observation has led to increased confidence in operating the system in spite of accumulated damage. The approach presented in the paper can be used by the industry to understand the risk involved instead of taking decision based on remaining life computed using deterministic approach. The reliability based approach provides a qualitative assessment of extent of damage and hence assists in making a decision for risk based inspection and replacement.

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