Study On Reliability Of Defective Oil&Gas Pipeline

With the progress of social piping applications in oil and gas distribution plays an important position can not be ignored,since the rise in oil and gas fields now have a storage capacity in some areas has basically been depleted,so some areas on the regional cooperation is a part of the pipeline across the region are one after another the planning and construction,these guidelines for future pipeline field road,pipeline transportation resources can maximize the utilization of the catalyst,economic development in the world.Oil and gas pipeline in the transportation is very important tool,with the development of the economy,but also in the pipeline is gradually increasing,so the management confusion appeared in the pipeline management,at the same time because of the service time of oil and gas pipelines accounted for relatively large,pipeline leakage accidents occur frequently mainly by corrosion,stress loss as a result,defect.Especially the natural gas transportation pressure line breakage cracking,the line becomes large if the damage cracking,hundreds of times the transmission medium volume will be within a short period of time,the instant change of volume brought about tremendous energy,will cause an explosion and fire,will lead to very serious consequences.The cause of the accident is caused most fracture problems,so the main research and the problem is closely related to the fracture crack problem,by comparing the intuitive easy to measure method of crack near the complex mechanical problem is simplified to obtain area near the crack stress intensity factor(K),and then to the analysis of pipeline fracture problems.This paper describes the fracture accident of several domestic and foreign oil and gas pipeline representative,thus influence the occurrence of these accidents brought to people's life safety can not be ignored,but the oil and gas pipeline in the process of manufacture and installation will inevitably have cracks,and these defects during the service to continue by various forces in the pipeline,in the process of crack will extend,and even large-scale fracture,the theoretical foundation in understanding the mechanism of the fatigue crack propagation law and the mixed type should be studied in the propagation process of force condition is very necessary.By using the ANSYS software to establish the three-dimensional finite element model of oil and gas pipeline,using the finite element method to(stress intensity factor)were determined and analyzed,and further on the relationship between stress distribution and crack opening displacement of inclined cracks is analyzed.The experiments for measuring crack surface opening and slip of two direction displacement,and then by calculating the I type stress intensity factor and II stress intensity factor analysis theory and experimental results finally the simulation results of I and II.