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Management of and risk evaluation on long-distance gas pipelines related to regional level upgrading

??In order to manage and control effectively the change of gas pipeline risks caused by the regional level upgrading, it is necessary to establish a management process, develop a risk evaluation model and propose risk control principles according to the basic principle of pipeline integrity management, combined with the regional level change conditions of gas pipelines. In this paper, a high-consequence zone was identified according to the regional level classification standard to perform classified management on the pipeline sections where the regional level is upgraded. Then, the risk level of the pipeline sections where the regional level is upgraded was evaluated. First, the failure probability of EGIG statistics was corrected by introducing the fuzzy language and its quantified value to obtain the total failure probability suitable for the specific pipeline section. Second, the vaporous cloud explosion model was adopted to make calculations based on the most serious accident consequence, and the fatality estimated based on 50% lethal rate of leakage was taken as the consequence grade evaluation criterion. And third, the risk level was evaluated by using the risk matrix based on failure probability and failure consequence. Finally, the risk acceptability criterion was introduced to analyze personal and social risks related to pipeline leakage and discriminate pipeline risk acceptability of regional level upgrading. Case analysis shows that risks increase with the upgrading of regional level. In the pipeline sections where risks increase after the regional level upgrading, it is necessary to decide whether to take safety measures according to risk management and control principles.