FERRIS, F. G., JACK, T. R., and BRAMHILL, B. J. 1992. Corrosion products associated with attached bacteria at an oil field water injection plant. Can.
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Corrosion products associated with attached bacteria at an oil field water injection plant F. G. F E R R I S ,T. ~ ~R.~ JACK, AND B. J . BRAMHILL Nova Husky Research Corporation, 2928 16th Street N.E., Calgary, Alta., Canada T2E 7K7 Received March 3 1, 1992 Revision received May 28, 1992 Accepted June 1, 1992 B. J . 1992. Corrosion products associated with attached bacteria at an FERRIS,F. G., JACK,T. R., and BRAMHILL, oil field water injection plant. Can. J . Microbiol. 38: 1320-1324. Attached populations of corrosion enhancing sulfate-reducing bacteria (SRB) and organic acid-producing bacteria (APB) were measured on steel plugs at an oil field water injection plant near Wainwright, Alberta. The sample plugs were colonized to. ca. lo6 S R B / C ~ Counts ~. for APB ranged from lo2 to 103/cm2. Scanning electron microscopic examination of the sample plugs revealed an uneven distribution of surface corrosion deposits. A thin iron sulfide layer covered most of the exposed areas. Thicker sulfur-enriched deposits occurred randomly. The bulk of the thicker deposits were smooth, whereas peripheral regions exhibited a porous texture. The elemental composition of the different regions was the same; however, bacterial cells were concentrated in the porous areas and were not found in the thinner deposits. In transmission electron microscopic thin sections cut perpendicularly through corrosion deposits, bacterial cells were found mineralized in successive stages by iron sulfides. The corrosion deposit matrix also generated strong C1 peaks in energy dispersive X-ray spectra. This entrainment of bacterial cells within a corrosion deposit matrix is consistent with the concept of bacterial enhancement of corrosion by removal of reducing power from iron sulfides galvanically coupled to the steel surface. Key words: microbial corrosion, iron sulfide, cathodic hydrogen, electron microscopy. FERRIS,F. G., JACK,T. R., et BRAMHILL, B. J . 1992. Corrosion products associated with attached bacteria at an oil field water injection plant. Can. J . Microbiol. 38 : 1320-1324. On a evalue les populations adherentes favorisant la corrosion par les bacteries sulfato-reductrices (SRB) et le developpement de bacteries productrices d'acides organiques (APB) sur des bouchons d'acier dans un plan d'in'ection d'eau dans un champ petrolifere situe pres de l'ordre de lo6 S R B / C ~ Le ~ . nombre d9APB variait de 10J a 103/cm2. En microscopie electronique a balayage, on a observe une distribution inegale des depbts de corrosion de surface. Une mince couche de sulfure de fer recouvrait la presque totalite des surfaces exposees. Les dep8ts plus epais et a plus forte teneur en soufre se retrouvent au hasard. La masse de ces dep8ts plus epais etait plus lisse comparativement aux regions peripheriques qui presentaient une structure poreuse. La composition elementaire etait semblable pour les differentes regions. Par contre les cellules bacteriennes etaient concentrees dans les regions poreuses et on ne les retrouvait pas dans les regions oh le dep8t etait tres mince. Lors de l'observation en microscopie electronique de coupes minces faites de facon perpendiculaire aux dep8ts de corrosion, on a retrouve des bacteries a differents stades de mineralisation par les sulfures de fer. Le profil de composition des dCp8ts de corrosion a revele des pics eleves de C1 selon les spectres d'energie de dispersion en rayons-)
