Simulation analysis of sensitivity for corrosion of pipe wall using electrical capacitance tomography technique

Abstract

Pipelines are major part of any oil and petrochemical industry. It is common to burry transportation pipelines under soil for mechanical protection. However, corrosion in soil can reach high rates and becomes a major loss especially in costal environments and wet soils. In this paper, a numerical simulation analysis of pipeline corrosion is developed by using a new technique for corrosion evaluation. This technique is electrical capacitance tomography (ECT). The electrical capacitance system consists of number of electrodes mounted on the outer surface of pipeline, radius-electrode ratio is defined as the ratio of inner and outer radius of pipeline. The electrodes will act as a capacitance detector and the resulting capacitance can be measured between the electrodes. This capacitance will therefore vary when the pipeline thickness changes with time (that is, when the corrosion occurs). The finite element simulation technology can be used to calculate capacitance value to obtain the capacitance-sensitive field distribution electrode sensors. The effect of pipe wall corrosion on sensor capacitance measurements is presented in this work. It is based on the finite element model. The simulation results are obtained using ANSYS and MATLAB software.

Keywords: Pipeline wall corrosion, Electrode sensors, electrical capacitance tomography, pipeline thickness changes, finite element simulation technology, ANSYS and MATLAB software.