The purpose of this study is to evaluate the basis for a quantitative risk analysis of the supply fleet of an Arctic offshore oil field. The design criteria of the supply fleet regarding the safety of the oil field are also of great importance. The study is focused on operation in the Piltun-Astokhskoye oil field offshore the North-eastern coast of Sakhalin.

In this study the starting point to safety analysis of an Arctic oil field is the definition of the tasks of the supply fleet. The most important tasks regarding the safety of the oil field are rescue and evacuation, firefighting, oil spill response and supply of the platform. Breaking ice around the platform (ice management) is also a very important task in Arctic areas. In the safety point of view the most important vessel of the supply fleet of an oil field is the standby vessel, which always stays in the vicinity of the platform.

The hazards of an Arctic oil field are presented. After this the most important accident scenarios in which the supply fleet has a great importance are studied. The chosen scenarios are evacuation of the platform, oil spill response and supply vessel -platform collision. The scenarios are evaluated in a brainstorming session. The participants of the session are experts in arctic marine technology and maritime safety. Based on the results of the brainstorming session the evacuation scenario is studied further. Special attention is paid to operation and performance of the standby vessel in winter conditions.

The most important result of the study is a list of environmental conditions, which should be considered in the quantitative risk analysis of the supply fleet. The significance of each environmental factor on the supply fleet operation is described. At last a principle for defining the optimal composition of the supply fleet is presented. The performance requirements of the supply vessels are also discussed