As an essential part of the natural gas supply chain, the safe and reliable operation of the natural gas pipeline system is vital to energy supply security. When accidents occur in the natural gas pipeline system, determining the maximum allowable repair time of the failed unit is a crucial factor in balancing maintenance resources against risks of gas shortage. Therefore, this paper proposes a methodology to determine the maximum allowable repair time for critical units of natural gas pipeline systems using gas supply reliability theory, considering system uncertainties as well as the line-pack effect. The methodology is composed of three parts. Firstly, the supply reliability indicators are proposed from the perspective of gas shortage. Secondly, the gas supply reliability evaluation model for the natural gas pipeline system is developed considering system uncertainties and the line-pack effect. Finally, the maximum allowable repair time is determined based on gas supply reliability and target reliability. Furthermore, a real natural gas pipeline system located in China is applied to confirm the feasibility of the methodology. The results demonstrate that the proposed methodology can serve as part of a Reliability Centered on Maintenance (RCM) analysis and provide guidance to support maintenance managers in making data-driven decisions.
Keywords natural gas pipeline system, supply reliability, Reliability Centered on Maintenance, maximum allowable repair time