DefinePK

Abstract

Natural gas with acid gases (H2S, CO2, and organic acids) transported in the pipeline leads to a corrosion process and produces sludge accumulated in the pipe. This study was devoted to understanding the corrosion of API 5L X65 pipelines by examining the resulting sludge. The collected sludge was then treated and dried to become powder. Subsequently, the powder was subjected to XRF, XRD and SEM-EDX analysis for experimental material characterization. The obtained sludge contains major elements of Fe, Ca, Mn, and S according to the XRF analysis, while the resulting particle shape was in the form of rounded, irregular aggregates with a size of 8.427 µm and 6.775 µm while EDX results show the most chemical composition of specimens corresponding to elements of Fe, C, and O. The XRD Rietveld method confirmed that magnetite (Fe3O4) is the main crystalline mineral found in the corrosion product, while some minor products (e.g.CaCO3, FeCO3, and FeS) could be not detected under detecting limit of x-ray diffraction study. Evidently, the pipelines of API 5L X65 had been subjected to mainly CO2 corrosion, but a further assessment of this mechanism is still needed for a failure prediction and corrosion protection program of pipelines.