With this paper we will summarize the operational experience of FPSOs in Norwegian waters as seen from the regulatory point of view. Reported incidents, challenges and lessons learnt in the years after the first production vessel came on stream will be described, and utilized in an assessment of risk. At the end of 2000, five production vessels are in operation on the Norwegian Continental Shelf. Norne FPSO has been on location in the Haltenbanken region since 1997. Petrojarl Varg has been on location in the North Sea since 1998. Asgard A has been on location in the Haltenbanken region since 1998. Balder FPU and Jotun A has been on location in the North Sea since 1999. In addition, there are three floating storage units; Polysaga, Njord B and _Asgard C. Totally these vessels represent more than nineteen years of offshore experience.
A production vessel was first introduced on the Norwegian Continental Shelf (NCS) in 1986. Petrojarl 1 was applied to do production testing in the period September 1986 to June 1988 at the Oseberg field, and December 1989 to October 1991 at the Troll and Balder fields. However, a permanently installed FPSO was first introduced in 1997. The FPSOs on the NCS are all turret moored. Accordingly, are all weather-vaning, which means that the turret is located in the forward half of the vessel, and waves and wind will normally keep the FPSO with its bow towards the weather. Aiding the vessel to maintain a steady controlled course, the FPSOs are equipped with thruster assistance systems. Three of the FPSOs are located in the North Sea in water depths from 85 to 125 metres, the other two are located in the Norwegian Sea in water depths of 300 metres and 380 metres.
