Quantitative Risk Assessment Of Nanwanzhong Gas Pipeline (buried)

Until the end of 2015, the length of completed long-distance oil&gas pipeline are 120 thousand kilometers. Among these, the gas transmission pipeline account for 72 kilometers of all the pipelines. Now, the basic pipeline network of our country has been formed. With the rapid development of natural gas pipeline system, the safety problem has gradually emerged, which we need to pay close attention to. Casting quantitative risk evaluation of pipeline can improve the capability for accidents predication and reduce the loss caused by the accidents as little as possible. Therefore,it is of great significance to study the quantitative risk evaluation of pipeline system.This paper ensured the risk factors of pipeline through the statistic analysis of the failure data of gas pipeline and the fault tree analysis. Then based on the failure probability which set by the professors, and combining the consideration of the relativities of each basic events, we calculated the failure probability and analyzed the consequent of the accidents in the high risk uint. Thus we accomplished the quantitative risk evaluation of the pipelines, and compared the results with that of the Kent’s scoring methodThe following content are mainly considered:(1)We introduced the basic situation of Nan-Wan-Zhong gas transmission pipeline briefly, and found out the hazardous factors in the project, then divided its units for risk assessment.(2)We cast a FTA on the pipeline, and combined with the the failure statistic data of the main gas transmission pipeline both at home and abroad, we summarized the main factors that may lead to pipeline failure. Those data provided the basic data for the pipeline failure probability model.(3)We took an overall consideration of the influence that risk factors have on failure probability, and based on the failure probability which set by the professors, and combining the consideration of the relativities of each basic events, we calculated the failure probability of each part of the pipeline.(4)Through the investigation and analysis of gas diffusion and explosion accidents both at home and abroad, we analyzed the typical failure model. And through the simulation software, we simulated the leakage accident and the explosion failure of Nan-Wan-Zhong gas pipeline system respectively. Then calculated the influence area and damage probability of pipeline failure.(5)Compared the results with that of the Kent’s scoring method, we analyzed the rationality and feasibility of the risk evaluation methods.