Bowtie methods and their application in oil and gas engineering

Bowtie methods are very popular in the field of risk assessment in recent years. They are dedicated to the risk quantification and calculation in the cases without sufficient data so as to realize the dynamic risk assessment, which is consistent with the development aim of risk assessment methods in the field of oil and gas engineering. In this paper, bowtie methods were illustrated from the aspects of definition, basic elements and classification. Then, the basic forms and application conditions of two bowtie methods were introduced respectively, i.e., direct cause-effect relationship bowtie and fault tree-event tree bowtie. It is pointed out that bowtie methods are advantageous for covering all the main contents of the risk management process. Based on three main research directions, the basic theories of qualitative, quantitative and dynamic bowtie methods and their application in the field of oil and gas engineering were reviewed. The qualitative bowtie method is still widely used for the systems which are not qualified for quantitative risk analysis, or for the safety management projects which are aimed at risk identification and risk situation communication. The quantitative bowtie method is mainly combined with the fuzzy theory to solve risk quantification and calculation when the data is insufficient or dependent and experts are limited in knowledge. The dynamic bowtie method is mainly combined with the Bayesian network to update risk assessment results in real time. The research results provide support for the development and perfection of risk management methods in the field of oil and gas engineering.