Study on corrosion properties of pipelines in simulated produced water saturated with supercritical CO_2

摘要

This work aims at systematically investigating the corrosion properties of three pipeline steels in static simulated produced water (SPW) saturated with supercritical carbon dioxide using weight-loss tests. SEM, XRD and XPS were employed to study the chemical composition and structure of the corroded surface. The results showed that the corrosion rates of the tested steels significantly decreased with increasing the exposure temperature and time in static SPW saturated with SC-CO_2. The surface film on the corroded surface, which markedly influenced the CO_2 corrosion behavior of the samples, was mainly composed of (Fe, Ca)CO_3 and α-FeOOH. Inhomogeneous element distribution of carbon, oxygen, calcium and iron in the surface film was observed. (Fe, Ca)CO_3 formed at a lower temperature was more stable than that formed at elevated temperatures.