Corrosion behavior and mechanism of N80 steel caused by sulfate reducing bacteria in CO2-saturated shale gas field produced water at 60℃

Abstract

Abstract The corrosion of steel caused by sulfate reducing bacteria (SRB) in shale gas environment is one of the big factors leading to the service failure of pipeline steel. However, the related studies of SRB corrosion especially at a high temperature are still poor. This paper aims to investigate the effects of SRB on the corrosion behavior of N80 steel in CO2-saturated simulated shale gas produced water at 60°C by weight loss, 3D microscope,electrochemical impedance spectroscopy (EIS) and polarization curves and so on. Results showed that the corrosion rate of N80 steel in the presence of SRB was greater than that of the abiotic control specimen. SRB cells and the inhibitive organics could have a competitive adsorption on the steel surface. The adsorption of inhibitive organics on steel in the abiotic condition caused a slight corrosion of the control specimen. While the adsorption of SRB cells as well as the subsequent formation of biofilm have accelerated the localized corrosion of specimen. Therefore, steel corrosion is accelerated in the presence of SRB at a high temperature.