Natural Gas Pipeline Reliability Analysis Based On Utility Theory

The failure of buried onshore natural gas pipeline causing by corrosion will inevitably result in a corresponding loss of economic assets to the countries and peoples.What pipeline companies most concerned is the safe operation of the pipeline reliability,but it is impossible or unnecessary to improve the safety reliability of corroded pipe blindly and to maintain and replace the pipe with defects in advance, because of limitations of the economic strength and staff input. In order to ensure the run of the natural gas pipeline corrosion economically, safely and reliably, the article studies the corrosion of pipelines based on safety and reliability of utility theory, and the work of this thesis can be illustrated as follows.Firstly, we study the reliability of corroded pipes by analyzing the gas pipeline accidents and the causes. We first study the remaining strength and remaining life of the natural gas pipeline corrosion, the author will use first amendment adopted guidelines to obtain ASME B31 G residual strength of corroded pipes, and then will use gray Markov theory to predict the remaining life of the pipeline corrosion based on the residual strength. In order to ensure economy of the pipeline corrosion’s reliable operation, we introduce the utility function theory to study how economic and reliable operation of pipeline corrosion.Secondly, to obtain external loss values of defective pipeline with function failure required by utility theory, we first need to establish the failure probability model of corrosion pipe for the risk assessment of defective pipelines and then we calculate and analysis economic losses, loss of life, environmental damage after the failure of the pipeline in accordance with the failure hazards model, and according to the relationshipbetween risk, loss and corresponding probabilities, we evaluate external loss values through the quantitative assessment.Thirdly, based on the predicted value of the remaining life about the natural gas pipeline, as a preconception to sacrifice the remaining life of corroded pipes, we use utility theory to determine the internal economic losses of pipeline companies when the pipes of the remaining life are early replaced, we contrast and analysis between the external loss values and internal economic losses to determine the best time when corrosion pipes are replaced.Finally, by using real world case, we proved the effectiveness of the proposed method.