Fuzzy Logic Based Risk Assessment For Shuttle Tanker Offloading Operation

Due to the continuous rising demand for crude oil globally, together with the situation that the land-explored oil cannot cover the current world demand, offshore oil exploration has become increasingly prevalent, which is now an important industry for global economy. Far from the land oil exploration, ocean-explored oil needs to be transported by specific reliable ways to guarantee the steady supply due to the fact that oil platforms are far away from the land. There are two major ways for ocean-explored oil transportation: by pipeline and by shuttle tankers. Due to some geographical and technical limitations, shuttle tanker transportation has been the selected way to transport oil in China coastal regions. To successfully transport the oil, shuttle tankers need to pick up oil at the oil platforms and then move to the oil storages on land. However, shuttle tankers for offshore oil transportation play a key role in ensuring supply safety. During offloading operation processs, collisions between shuttle tanker and FPSO(Floating Production Storage and Offloading) always happen because of poor shuttle tanker manipulation and risk management. Further research and actions need to be taken to quantify the risk of shuttle tanker offloading operation and to reduce it. Hence in this paper, we aim to propose a risk assessment model for shuttle tanker offloading operation to quantify and reduce the operation risks.To effectively prevent the collisions between shuttle tankers and FPSO(Floating Production Storage and Offloading) from happening, a Fuzzy Logic based shuttle tanker offloading operation risk assessment model is proposed, which incorporates 3 major factors: environment factor, vessel condition factor and human factor. This proposed model also incorporates wind, vessel age and on duty staff factors as input factors to improve the objectivity. By pre-defining the “IF-THEN” rules, the model could quantify the risk of offloading operations. Finally, 2 real-world cases are applied to test the feasibility and validity of the model, results have shown that the model output is well fitted to the real case.The models proposed in this paper can be effectively applied in practice. It provides a theoretical basis for shuttle tanker transportation management and future research. This paper has done a preliminary but useful research on the field of shuttle tanker offloading operation risk management, and has established an effective risk assessment model. Case study results haves shown that the proposed model could be properly applied in real cases. Our research has brought some certain help to other researchers and lays the foundation for the future research.