Analysis of pit and its effect on electrochemical corrosion reaction in oil and gas pipelines

Abstract

A parametric pit design in the outer surface of the oil pipeline buried under the soil atmosphere is investigated. This study analyzes the effect of pit size and corrosion contours to evaluate the metal degradation due to various characteristics that impact the corrosion on the oil pipeline. A 3D design of the model has been chosen, and its geometry is modeled in COMSOL MULTIPHYSICS, and appropriate meshing is done before computing to analyze impact of pit size and electron current density in oil pipeline. The behaviour of the pit design was then analysed using various parameters such as electron current density, corrosion rate, the impact of the pit size in localized area. The current findings in the study shows that risk of metal degradation and the depth of the pit size gives a relationship for corrosion in the localized area and the risk for pitting corrosion can be reduced by improving pipeline condition monitoring.