Location estimation of coating defects and mitigation of induced AC voltages along buried gas pipeline

Abstract

In this study, determining the location of coating defects and severities is evaluated using measurements along the Jordanian buried gas pipeline. Induced alternating current (AC) voltages and current densities along the pipeline are investigated using analytical and practical data under normal operation of the overhead transmission line. Since the induced AC voltages depend on the load currents, it is worthy to determine the actual load current during the lifetime of the pipeline. Accordingly, the forecasting of pipeline-induced AC voltages is investigated using the least square method. The investigation is carried out in order to expect the future effects on the gas pipeline. The mitigation of induced AC voltage based on inserting polarisation cells (PCs) along the pipeline is evaluated. The results show that an agreement between the measured and calculated induced AC voltages is achieved with and without PCs. Based on the forecasting of induced AC voltages and current density along the pipeline, determining the number of PCs and allocations is suggested for the future years. This study increases the lifetime of the pipeline as well as decreases the maintenance cost.