Risk evaluation of oil and natural gas pipelines due to natural hazards using fuzzy fault tree analysis

Oil and gas sector plays a major role in a country's economy. The development of large transmission pipelines for onshore and offshore gas transport is executed rapidly. These pipelines are vulnerable to natural disasters and can have a serious impact on the environment. The Potential damage to the pipeline infrastructure may contribute to increased risk of spill and thus can have an impact on the environment. Hence, the structural integrity of these pipelines is of great interest to the oil and gas companies, governments, and various stakeholders due to the probable environmental, infrastructural and financial losses in case of a structural failure. Fault tree analysis is an important risk assessment technique which treats the failure probabilities of the components as exact values for estimating the probability of the occurrence of a top event. Due to the lack of historical data for calculating the failure rate of pipelines due to natural hazards, this study aims to analyze the probability of pipeline failure by Fuzzy Fault Tree Analysis (FFTA) with expert elicitation. Fussel-Vesely Importance measures were utilized to rank the cutsets. The proposed FFTA framework was used to analyze the occurrence of top event even in the absence of historical probability data. The results are expected to be helpful to the safety professionals while making decisions related to the risk management of oil and gas pipelines.