(77c) Enhancing Offshore Safety: A Description of the Offshore Major Accident Risk (OMAR) Model

Past incidents within the oil and gas industry have demonstrated the importance of assessing and managing major accident hazards. BP has undertaken to drive the principles of inherently safer design and continuous risk reduction into its operations, and these processes are underpinned by a comprehensive understanding of the factors that affect major accident risk. BP has developed a process for assessing offshore risk and has applied it to its offshore facilities to identify the key risk drivers and to provide guidance on how those risks can be effectively mitigated. The paper describes this process, illustrated by some practical examples. Compared to onshore analysis, the assessment of offshore risk presents particular challenges such as near-field hazard effects, time-dependence, escalation, distinctive non-process events and a genuinely 3D environment. In 2008 BP engaged a technology consultancy to work with internal subject matter experts in developing a 3D model to implement this offshore risk assessment process. Based on consistent rule-sets, the model allows a variety of facility types to be spatially represented, accounting for dimensions/properties of decks, walls, enclosures, refuges, egress routes and evacuation facilities. The location of hydrocarbon systems and associated inventories are specified as well as the distribution of people during a range of operational states. Risk reduction options on operational plant or new designs can be modelled and the benefits objectively assessed. The paper includes examples of the model's application.