COMPARITIVE STUDY ON FATIGUE CAPACITY OF CONVENTIONAL AND HEMISPHERICAL HULL STRUCTURE FOR FPSOs

Abstract

In recent decades the use of ship type offshore structures for the production and storage of oil and gas has become a common method even in harsh environments. Moored permanently at deep seas, these FPSO units should be able to survive the most critical environmental conditions (violent storms, hurricanes, irregular waves, etc,) for years together. Therefore, the important requirement for FPSO hull is the desirability to remain on the deep sea station for the duration of the field life, without the need for dry docking. In these situations, FPSOs are becoming more vulnerable to fatigue failures due to cyclic loads from environmental conditions and operating cycles. Therefore, the first and easiest step to mitigate the impact of these fatigue loads could be refining the shape of the hull structure for FPSOs.Therefore, in this study, a parent conventional hull is taken and an equivalent hemispherical hull, which could be a refined shape hull structure, is created with equal volumes. In o...