On the Risk of Structural failure on Norwegian Offshore Installations

The purpose of this paper is to review the worldwide historical structural failure data in the 1990s on offshore structures, and compare this with the present risk analyses of Norwegian offshore structures. The paper describes an overview of registered accidents to offshore structures based on the databases WOAD and CODAM. The accident data is given for fixed platforms, jack-ups and for floating platforms. Estimates of risk level in annual frequencies and PLL values are given for each platform type. The paper concludes that: · The risk connected to marine operations and structures give a significant contribution to the total risk. · The historical risk to marine operations and structures is significant higher than the results from risk analyses. · Neither component nor system based reliability analyses of structures give adequate descriptions of the real risk connected to structures. · Human errors are probably the dominating cause of accidents connected to structural failure