A systematic method for assessing the operating reliability of the underground gas storage in multiple salt caverns. (October 2020) - Yu, Weichao
Highlights: A systematic method is developed to assess the operating reliability of the UGS. The ability of the UGS to perform the gas injection-production task is evaluated. Thermal-hydraulic characteristic and operating state uncertainties are considered. A numerical example based on a real UGS is applied to illustrate the method. Abstract: In this study, a systematic and comprehensive methodology to assess the operating reliability of the underground gas storage in multiple salt caverns is developed, and both the thermal-hydraulic characteristic and the operating states uncertainties of the gas storage are considered. This method consists of the thermal-hydraulic analysis of the gas storage, the unit failure probability estimation, and the operating reliability assessment of the entire system. Firstly, the thermal-hydraulic analysis of the underground gas storage during the gas injection and production cycle is undertaken, which is used to obtain the operating parameters and determine whether the operational constraints are met. Thereafter, the failure criterions and the corresponding limit state functions of the salt cavern and gas injection-production well are established to calculate their failure probabilities. Finally, the reliability calculation algorithm of the k -out-of- n: G system is employed to assess the operating reliability of the gas storage in multiple caverns. Furthermore, a numerical example based on a real underground gas storage is applied to confirm the feasibility of the methodology, and the ability of the gas storage to perform the specified gas injection and production function is evaluated. The assessment results indicate that the operation scheme about the number of caverns selected to perform the required task, has a significant impact on the operating reliability of the underground gas storage.