Seismic Security Study Of Corroded Oil Pipeline

With the further study on the exploration and development of oil fields，some oil fieldsgone into the later period for developing gradually. The corrosion problems of oil pipeline aremore and more prominent. Earthquakes occurred frequently in recent years, such asWenchuan earthquake and Yushu earthquake, etc. So it is particularly important to study onthe seismic performance of corrosive pipeline.First of all, the principle of corrosion and corrosion type of pipeline and the form offorces in the pipeline under the earthquake forces were brief introduced in this paper, sometypical damage caused by earthquake in history were described, too. The finite elementsoftware ANSYS which was used in this paper was introduced and the analysis model whichwas pipeline-spring model this paper adopted was put forward, too.The second chapter introduced the theoretical model and solid model of the pipe and soil.The theoretical analysis method in the model of this paper adopted the method of seismiccode and the time history analysis of structure adopted the method of Newmark intime-integration method. Pipe used in the solid model adopted the Solid45of ANSYS tosimulate when ignore the effect of fluid in the pipes under the earthquake. The soil around thepipeline all used soil spring which was the unit of Combin39to simulate. This article studythe influences of corrosion defects to the seismic performance of pipeline through the historyanalysis on acceleration, displacement and stress response of some typical points and theconcrete stress-strain numerical analysis.The third chapter mainly introduced the influence of corrosion parameters to theseismic performance of the pipeline. These corrosion parameters include: the corrosion depthof pipeline, the surface size of corrosion, the location of corrosion, the venue type which waslaid of corrosion pipe and the shear wave velocity of soil. This article discussed the influencesof various parameters to the seismic performance of pipeline through the time-history analysison acceleration, displacement and stress response of some typical points and the concretestress-strain numerical analysis.The forth chapter compared the model results with ASME B31G and API579ofstandard method, in order to determine the security of the pipeline in all cases, and providethe corresponding reference data to judged whether the pipelie can continue to service. Andthen, this chaper discussed the applicability of appropriate criteria for the defective pipelineunder seismic action.