Strength Assessment of Corroded Pipelines — Finite Element Simulations and Parametric Studies

Abstract

Pipelines are one of the most efficient means for transporting hydrocarbons from one point to the other. However, there is a great risk of pipelines operation failure due to the detrimental effects of corrosion. At the point of corrosion, the pipe wall becomes thinner and loses its mechanical resistance. In such cases, reliable defect assessment methods are necessary to decide whether to resume continual operation or to shut down for maintenance or replacement. However, the available assessment methods are over-conservative, which enforce either unnecessary maintenance or premature replacement. Furthermore, the defect assessment methods should not only ensure safe operation, but also optimized operation cost. Therefore, a new assessment method was developed based on the nonlinear finite element (FE) analysis and a parametric study of geometric parameters related to the corrosion defect. The new method was validated with burst test database, which can predict the burst pressure of corroded pipelines with better accuracy and consistency.

Burst capacity analysis of pipeline with multiple longitudinally aligned interacting corrosion defects subjected to internal pressure and axial compressive stress

“…Next, a symmetrical quarter model was used as it reduces the simulation time without compromising the results obtained from the finite element analysis (FEA). The method of using a symmetrical quarter model has been successfully employed by Belachew et al [14] for pipelines with single corrosion defect subjected to internal pressure. For this study, Autodesk AutoCAD was used to design a symmetrical quarter model to represent the actual pipe geometry.…”