http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Statistical Modeling of Corrosion Failures in Natural Gas Transmission Pipelines
Natural gas pipelines are a critical component of the U.S. energy infrastructure. The safety of these pipelines plays a key role for the gas industry. Therefore, the understanding of failure characteristics and their consequences are very important for designing future operations, operating expenditure, and maintenance decisions. The oil and gas industry spends billions of dollars annually for the corrosion-related cost of the transmission pipelines, the costs which increases due to aging and deterioration processes in pipeline networks. Therefore, pipeline operators need to rethink their corrosion prevention strategies. These results of corrosion failures are forcing the companies to develop accurate maintenance models based on failure frequency. Statistical methods for modeling pipeline failures and proper maintenance decisions play a key role in future safety of lines, to reduce the rate of occurrence of failures, and the cost-effective operation of pipelines. This thesis is focused on two challenges. The first challenge is to estimate the failure rate of natural gas transmission pipeline networks from the previous incidents' data in the United States. A specific objective of this part is to determine the characterization of the failure modes of the transmission pipelines, and to develop the statistical models based on the reliability of a repairable system. The second challenge is to develop the optimal preventive replacement actions by using well-developed optimization models. The objective of the second part is to choose appropriate maintenance policies based on the statistical models and to find the optimal maintenance policies. In this thesis, two of the most commonly applied stochastic models, which are the homogeneous Poisson process and the power law process, are used for the estimation of the failure rate. The point and interval estimators of the failure intensity function are provided and the accuracy of the stochastic models is tested for each determined failure mode. Finally, appropriate maintenance models will be presented for planning preventive maintenance and replacement activities for a repairable and maintainable system. It is assumed that pipeline systems could be restored to operation requirements by some minimal repair process instead of replacement after each failure. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/152566
Master of Science Texas A & M University 2014 http://hdl.handle.net/1969.1/152566