Met-ocean Study for Reliability of Jacket Platform Regression Analysis

Over 60% of PETRONAS Carigali Sdn. Bhd.
(PCSB) operated fixed jacket platform installed in Malaysia
water regions had already been put into service for more than 20
years, where their design life is only 20 – 25 years. In order to
extend the service life of these aged platforms, their current
structural integrity conditions need to be assessed. Reliability
analysis is emerging as one of the popular methods to review the
strength of a structure. In this study, the reliability indexes of an
offshore structure at different environmental loadings are
compared. Besides traditional combination of 100 year wave and
100 year current, combination of current of 10 year associated
with 100 year wave are analyzed. Monte Carlo Simulation and
First Order Reliability Method (FORM) are used to generate
reliability index and the probability of failure of the platform. In
addition, three different formulations of environmental load
response function are discussed. Regression analysis is
performed in MATLAB to obtain the response function.