Risk Assessment Of Town Gas Pipeline Networks

As a sort of energy of high quality and efficiency, it is certain that gas will play an important role in the energy structure of the 21th century, thus if our country would like to develop economy, we have no choice but to speed the construction of town gas networks. In consideration of gas is poisonous and flammable, if gas pipelines which buried under the city full of people ground leak, there would be some serious accidents such as poisoning, fire and blast. Then the incidents will cause casualties and property loss. As a result, risk assessment for town gas networks is necessary and in line with which we can take relevant prevention, maintenance and management measures to change the town gas networks maintenance plan from blind and maintenance into provisional and active service. What's more, the leakage of gas pipelines will decrease and the reliability of town gas networks operation will increase.At first, the research status of oil and gas pipelines risk assessment has been introduced, at home and abroad. Then, the relevance basic theories have been analysised, including the definitions of risk and risk assessment, the characteristics of various kinds of risk assessment methods, the traits and steps of two methods how to determine the weight of every index.In this paper, the characteristics of city gas networks have been analysised and the applicability of quantitate risk assessment methods have been compared with each other. Then, the fuzzy-multiple method has been chosed as the main risk assessment method. Take Changchun for example, based on the relevant information of gas networks and literatures, the risk assessment models of steel, cast iron and PE pipelines have been put forward, the weight of every of risk assessment index has been determined using expert and gradation method and the standard for evaluation of each index has been confirmed. The risk of mid-press cast iron gas pipeline networks in Changchun Oudao has been assessed and some relevant suggestions have been put forwords.Based on the analysis of the necessary that the data base about city gas networks should be built and the misdistance compared with abroad, the data base of Changchun gas networks which model is B/S has been built using dynamic pages technology.The definition, necessary and characteristics of risk management have been analysis based on which risk management has been introduced into city gas networks daily maintainance and management and the simple flow chat of risk management has been put forward, in which suggestions aimed at the gas company, the government and other units, based on the results of town gas networks'risk assessment is thrown out in order to enhance the reliability of gas distribution networks.The methods and the conclusions in this paper may make sense for the risk assessment, the building of data base and risk management of city gas networks.