| dc.description.abstract | In the last decades, energy request has been increasing due to a continuous economic and social progress. Although the increasing use and development of renewable resources, the primary energy resource is considered to be fossil fuel and its request still is expected to grow. The request led the oil and gas companies towards unexplored regions, while facing increasingly strict environmental and safety regulations. Therefore, new technologies have been focused on efficient and safe production and on digitalized and autonomous solutions. This work investigates advanced methodologies for risk analysis and risk management and their application to offshore integrated systems, including technical and organizational components. Different aspects of the challenges that oil and gas industry is facing are explored and solutions for quantitative assessment are proposed. The interaction between new technologies, humans and the environment is considered for the definition of a dynamic risk assessment approach based on exogenous and endogenous information data. Part of these data can be collected by new digitalized monitoring technologies, which are studied as a support to safety barrier management from a system engineering perspective. Since safety barriers may consist of both technical and operational systems, an advanced method for thorough performance assessment was developed. Special focus has been given to escalation scenarios on offshore oil and gas platforms. The methodologies are applied to existing industrial cases to prove their suitability and effectiveness for advanced risk assessment and management.
The findings show how the comprehensive system approach and data analytics can be useful for risk management and prevention of major accidents. They are considered especially valuable for cases where special requirements need to be met. The development of risk indicators to assess the conditions of safety barriers, both technical and operational and organizational one, and then introduce them in the dynamic risk evaluation using the Risk Barometer technique has been proven to be effective in showing risk metrics fluctuations (for example, PLL variations due to different barrier status). Different methods for the evaluation of technical, operational and organizational barrier performance has been developed and assessed for fire escalation prevention. The Risk Barometer example proves that risk may be periodically evaluated by analyzing the safety barrier conditions, supporting decision making and eventually improvements and/or actions. Factors such as meteorological onditions (as ice and wind) have been taken into account in the evaluation of fire prevention and mitigation barriers. The modified performance parameters of safety barriers allow a more detailed frequency assessment of escalation scenarios. Periodic revision and update of relevant risk indicators may drive the identification of critical safety issues in an installation else hidden involving technical and managerial aspect. Different factors enter the game while assessing barrier performance. This thesis systematically assesses how the meteorological conditions of the environment where the installation operates may affect the barrier effectiveness. Barrier conditions due to factors such as wind and ice can be update periodically (for instance based on the season). This provides a more detailed risk picture, supporting operational decisions. Given the many different stakeholder involved in the operation of an oil and gas installation, a top-bottom approach for safety risk management have been applied from system engineering. This has been proved to help in the management of information flow from subsea sensor networks to control room and onshore offices for an oil spill response scenario.
Every methodology proposed in the present thesis have been tested on real casestudies for assessing its potentiality of improving risk management. Limitations have been highlighted and discussed and eventual improvement suggested. | nb_NO |
