Corrosion of carbon steel induced by a microbial-enhanced oil recovery bacterium Pseudomonas sp. SWP-4

Abstract

Pseudomonas sp. SWP-4 has been proved to enhance oil recovery effectively. However, corrosion to oil wells or pipes needs to be evaluated when SWP-4 is used. This study investigated the corrosion behavior of carbon steel induced by SWP-4. Results indicated that a mild effect on corrosion occurred in medium with SWP-4. Electrochemical parameters (E_corr, I_corr, and R_ct) suggested that SWP-4 promoted the corrosion in the exponential phase in the fastest growth time. Surface morphologies and corrosion products were detected by using scanning electron microscopy and energy dispersive X-ray spectroscopy. Moreover, this study proved that oil–cell-free fermentation broth could inhibit the corrosion and the growth of sulphate-reducing bacteria and saprophytic bacteria.