Offshore accidents and effects on their performances

Marine accidents are some of the risk sources on human life at sea and also make the founded budget to be sank to the deep. In order to prevent these damages and losses, it is necessary to do a proper understanding of these accidents. Offshore systems as of the main parts of ocean structures and their accidents are considered here in this paper. From 1975 some data showing offshore accidents are captured in the worldwide offshore accident databank (WOAD), which are the main data bank to be used in this study. These data are about offshore damages and collapses due to fires, blowout, anchor failure, capsize, explosion, etc. The main scope of the study is on fixed offshores, named jackets which are used in the Persian Gulf for oil production. Fire is considered here and a mathematical model for fire distribution is derived. Heat transfer within the structure in three different ways including: radiation, convection, and conduction will be considered. Surrounded environmental winds, waves, earthquakes and others strengthen the heat flux and its effects on the structure. In this research a jacket named Forozan, located in the Persian Gulf, loaded under gravitational effects of the fixed parts and moving parts, while considering environmental like winds, waves, etc is considered, if fire is distributed at the main top deck. Finite element analysis, using ANSYS is performed to derive thermal stresses and strains in the structural members of the jacket, and the results will show how to modify the weak point in the structure to prevent collapses and damages.