Risk analysis and Assessment of Wellbore Integrity Failure in Underground Gas Storage Based on Bayesian Network

Abstract

Well integrity assessment plays vital role in the risk management of gas storage wells, which has emerged as a key topic of political and scientific discussion in the gas industry. However, the current research did not provide quantized assessment of failure probability of well integrity. To quantitatively evaluate the failure risk of gas storage well integrity, the probability model based on Bayesian network is established and calculated incorporating the relevant historical statistical data of gas storage well integrity failure and Leaky Noise or Gate extended model. Besides, the risk priority evaluation criteria of well integrity are set up, combining with the analytic hierarchy process. And the risk judgment matrix is constructed to quantitatively evaluate the risk of wellbore integrity failure in gas storage. Practical guidelines and solutions derived from the results of the current study can be used for the design of the gas storage wellbores.