| The microbiological influenced corrosion in the inner surface of the pipes in the oil field is mainly caused by sulfate-reducing bacteria(SRB), iron bacteria(IB)etc. Among these bacterial, the anaerobic SRB is the most damaging that will lead to the corrosion perforation on pipeline, and its growth and reproduction will bring about the secondary pollution to the water, directly blockage the formation, and then will lower the oil recovery. It is really an efficient and easily to be to be realized method to apply antimicrobial coating onto the surface of the pipe. Therefore, this paper synthesized inorganic antibacterial materials and systematic researched its bactericidal properties to SRB. And then synthesized antimicrobial coating within this antibacterial materials by physically blending, and studied the antibacterial properties in order to inhibit corrosion in water system and prolong the life of the pipeline.Electrochemical methods, 3D microscope, fluorescence microscopy, SEM, XPS and other methods were used to investigate the microbiological influenced corrosion in the sewage system, the antibacterial bactericidal properties of copper oxide to SRB and the antiseptic properties of the copper oxide-based composite coating. The summary main researches are following:The content of SRB in the Daqing Oilfield Sewage was very high, and the rate of growth and reproduction was very fast, the amount of it reached the maximum quickly just at the second day during the culture. The optimum temperature for such bacteria was 37 ?, the optimum pH was 8.0, and the optimum salinity was 10 g / L. The MIC on Q235 pipe caused by SRB is very serious, at the beginning of the soak, SRB began to adsorbed onto the surface of the pipe, and then the biofilm was farmed, hence, the MIC was inhibited to a certain extent. With the increasing immersion time, the biofilm gradually flaked, so that facilitate the corrosion. There was no SRB detected sludge on the pipeline, and the main composition were calcium salt and iron oxides.Nano Cu2 O could effectively kill SRB, inhibiting their adhesion onto the surface of Q235 carbon steel, and slowing down the formation of biofilms. In this antimicrobial process, cuprous oxide did not react, and there was no Cu2+and Cu+ generate. So nano Cu2 O could easily adsorb onto the surface of SRB, pass into the interior of the cell, and then restrain the activity of the enzyme to inactivation achieve antibacterial purposes.Due to the addition of nano-Cu2 O, the coating resistance of composite coating was much higher than the solvent-free epoxy coating. That was mainly because the nano-Cu2 O blocked the microscopic pore formed during the process of solvent-free epoxy crosslinking, so that the corrosive media could not directly be in touch with the metal substrate, and then the shielding properties of the coating was improved. In addition, and with the extension of immersion time, the coating will swell, and the more and more nano-Cu2 O will gather to the surface of the coating and the interface of coating microscopic aperture and the corrosive medium, so that it can effectively kill SRB that absorbed onto the surface, inhibiting it's attachment to the metal surface. Thereby significantly inhibited the formation of biofilm on the surface of coating, thus effectively reducing the MIC on the surface of the metal substrate. |
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