This study used Finite Element Modelling (FEM) to determine the relationship between the burst pressure (Pb) of internally, circumferentially corroded pipelines, with the corrosion defect depth (d), pipe wall thickness (t) and the pipe diameter (D). After modelling X46 and X52 grades of pipes, the Pb estimated was compared with those determined experimentally and with industry standard models—ASME B31G (modified), RSTRENG, DNV F101, SHELL92 and FITNET FFS. The comparison specified a Root Mean Square Percentage Error (RMSPE) that ranged from 7.06% to 20.4% and a coefficient of determination (R2) that varied from 0.7932 to 0.9813. Multivariate regression was also used to compute a general linear relationship between the burst pressure (Pb) and (d/t), (L/D) and (L/"1270Dt). The resulting FEM burst-pressure model, developed with multivariate regression, was later used to estimate the expected allowable operating pressure of a corroded X46 grade pipeline over the lifecycle duration, for low, mild, high and severe corrosion categories. It was observed that the burst pressure retention ratio (Rr), which is an indicator of the reliability of the pipeline, decreased with the increase in (d) but did not show distinctive changes with the increase in (L). Considering the robustness of the FEM developed in this study, it can be concluded that it will be very vital for flowline design and pipeline integrity management.
Ossai, C. (2017). Finite Element Modelling and Retained Life Estimation of Corroded Pipelines in Consideration of Burst Pressures—A Fractural Mechanics Approach. Infrastructures, 2(4), 15. https://doi.org/10.3390/infrastructures2040015