The Influence of Sulphate-Reducing Bacteria on Surface Characterisation of Carbon Steel in CO2 Environment

Abstract

AbstractIndustries of oil and gas production have long faced a complex problem of CO2 corrosion; the most prevalent form of corrosion. The pipeline system environment, used to transport oil and gas, contains some levels of CO2 gas. This study inquires on the carbon steel surface characterisation (API 5L X65) in CO2 environment with the presence of sulphate reducing bacteria (SRB). For 10 days, the specimens underwent exposure in a culture medium with and without the bacteria. This study was investigated by using Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray Spectrometer (EDS), Infinite Focus Microscope (IFM) and X-ray Diffraction (XRD). The FESEM analysis proved sulphur presence on metal specimens exposed to SRB in CO2 environments which support the formation of FeS layer. The XRD test affirmed the formation of FeS in samples exposed to the SRB. Meanwhile, IFM showed that samples with the presence of SRB promote pitting corrosion.KeywordsPitting corrosionMicrobiologically influenced corrosionSurface analysis