A Simplified Reliability-Based Method in Estimating Losses to Fixed Offshore Oil Platforms in GOM

摘要

Past hurricanes like Ivan, Katrina and Rita indicate the need to evaluate structural performance on both qualitative and quantitative bases. This paper briefly emphasizes on the use of a structural reliability-based simulation technique combined with nonlinear pushover analysis to quantify losses. The simplified reliability-based method is introduced and used to estimate the vulnerability curve of a typical fixed platform. The verification of a 4-leg fixed platform is provided by using the damage reports from Hurricanes Katrina, Rita and Ivan in MMS Project Numbers 549, 578. The comparison of the results show the vulnerability curve is able to predict the reported damage incurred from Hurricanes Katrina and Rita within one standard deviation range. However, the damage ratios reported from Hurricane Ivan are out of the range due to the wave-in-deck factor which is not included in the model as well as the lack of correlation between wind and wave states observed. Overall, this study shows that the simplified reliability-based method is capable of predicting losses. The concept and procedure of this approach can rather simply be applied to other types of platforms.