Study On Risk Mitigation System For The Long-distance Oil/gas Pipelines

Risk mitigation contains two aspects of signification: firstly, it is to mitigate the probability of risk; secondly, it is to try to reduce the lost, once the risk has taken place. After accomplishing the assessment of the pipelines, this method, which is based on the analyses of the outcome of the assessment, is applied to finding out pipes with high-risk probability and factors that result in the failure on the pipes. On the foundation of the findings, we are able to provide corresponding measures for risk mitigation to ameliorate the adverse factors and to restrict the operation risk level of the pipelines to reasonable and acceptable scope. The purpose of this method is to mitigate the probability of failure on the pipes and to insure the safe operation of pipelines economically and reasonably.Aim at characteristics of the long-distance oil/gas pipelines, and beginning with the analyses of the factors that influence the risk level of the long-distance oil/gas pipelines, this paper illustrates the techniques for risk mitigation from two perspectives: the prevention to pipeline risk and mitigation of failure aftereffect respectively. Then, it establishes an elementarily consummate risk mitigation system for the long-distance oil/gas pipelines, and the main research content and conclusion are as follows:(1) Elaborate the background of pipeline risk assessment and risk management and analyze the significance of risk mitigation system; analyze overseas and domestic research on risk management of oil/gas pipelines, and propose some suggestions for risk management.(2) Define risk and describe acceptable criterion for risk; explain the purpose of risk mitigation and summarize the flow chart and research techniques of risk mitigation system; clarify the process for establishing risk mitigation system.(3) Constitute system of failure probability factors; constitute systems of factors which could reduce the risk about third party destroy, corrosion, design fault, construction fault, improper operation and natural calamity, respectively; constitute corresponding approaches for risk prevention and determine grade values according to the reasons of failure; calculate the degree of different approaches to failure probability in order to establish risk mitigation system.(4) Analyze the factors which influence failure effect, and constitute mitigation methods of failure effect according to situations of meeting an emergency, closure and management after an accident.(5) Illustrate the application of risk mitigation technique on pipelines from Lanzhou to Chongqing; calculate the risk value of subsection of pipelines from Lanzhou to Lintao, using software developed by program team and do risk mitigation on the base of the result.