One of the key challenges in preventing major process safety accidents in an operating plant is the lack of an integrated system/model that brings together the risks posed by the deficiencies / deviations on the safety critical barriers, for operational decision making. Based on this context, an exploratory study was undertaken to develop a model/framework for visualizing the accumulation of process safety risks arising from safety critical barriers impairments in petroleum facilities in Niger-Delta Nigeria. The results indicate that the process safety cumulative risk assessment framework/model offers a transparent mechanism for assessing and visualizing the cumulative risks arising from the barrier impairment problems. For the facility in the first case study, 3.2% of the total number of safety-critical barriers was deviated and the model revealed risk accumulation in the gas compression functional location. For the facility in the second case study, 1.7% of the total number of safety-critical barriers was deviated and the model revealed risk accumulation in the gas dehydration functional location. When applied properly, the model/framework will reduce the risk of major accident in petroleum facilities by (a) aiding better management of safety critical barriers deviations through improved risks visual and (b) eliminate variability in human interpretation of process safety risk levels. One improvement area identified in the model/framework is the need for a web-based software for automation of barrier impairment data collection and real-time visualization of the cumulative risk picture.
Keywords: cumulative risk assessment, major accident prevention, petroleum operations, process safety, risk visualization
