Research on residual strength of metallic oil and gas pipelines with uniform corrosion defects based on finite element method

Inview of the increasing corrosion of oil and gas pipelines with serrice years, the finite element analysis software ANSYS Workbench was used to perform comprehensive analysis on metallic oil and gas pipelines with uniform corrosion defects, so as to investigate the effects of axial corrosion length, circumferential corrosion length, corrosion depth and spacing of adjacent two defects on the residual strength of pipelines. It is shown that the longer the axial corrosion defect is, the lower the residual strength of pipeline is. When the circumferential corrosion defect is longer, it has less influence on the residual strength of pipelines; and when it is shorter, it can be treated as a crack. The residual strength of pipeline decreases rapidly as the corrosion depth increases. Two adjacent axial corrosion defects can be taken as a whole defect for the calculation of residual strength when their axial spacing is less than 20 mm. When the axial spacing is greater than 20 mm, the residual strength of pipeline corresponding to the two defects is calculated respectively and the smaller value is taken as the residual strength of pipeline.