Development of an Original Multi-Hazard Risk Assessment Methodology for Floating Production Storage and Offloading Vessel Operations in Nigerian Deepwater

Floating production storage and offloading vessels operating in Nigerian deepwater fields are exposed to concurrent hazards including structural failure, fire and explosion, mooring system failure, process equipment malfunction, and environmental extremes, and their risk assessment requires a multi-hazard methodology capable of capturing hazard interactions and common cause failures. This study develops an original multi-hazard risk assessment methodology for floating production storage and offloading operations in Nigerian deepwater, addressing limitations of existing single-hazard methodologies that do not account for hazard coupling effects. The research employs a design science research approach, developing the methodology through structured problem formulation with offshore safety engineers, theoretical methodology design, computational tool development, and application to a case floating production storage and offloading vessel operating in the Bonga deepwater field. The methodology integrates event tree and fault tree analysis for individual hazard pathways with a Bayesian network meta-model that captures interdependencies between concurrent hazard scenarios. A novel feature of the methodology is a dynamic risk update module that modifies hazard probability estimates based on real-time process monitoring data, enabling the risk assessment to function as a continuous risk management tool rather than a static point-in-time evaluation. Validation is achieved through comparison with historical incident data from Gulf of Mexico and North Sea floating production storage and offloading operations as analogous benchmarks. Keywords: multi-hazard risk assessment, floating production storage and offloading, deepwater operations, Bayesian network, dynamic risk management