ÇAĞRILI KONUŞMALAR / KEYNOTES Invited Speeches ... - TPJD

Investigation of Sulphate Reducing Bacteria in Petroleum Reservoirs of
Dodan, Garzan ve Silivanka Fields (Se-Turkey)
Esra İlhan Sungur 1 , Nihal Doğruöz Güngör 1 , Hakan Hoşgörmez 2 , Ayşin Çotuk 1
1 İstanbul University, Faculty of Science, Department of Biology, Fundamental and İndustrial
Microbiology, İstanbul
2 İstanbul Üniversitesi, Faculty of Engineering, Department of Geology Engineering, İstanbul
For metabolic activities, sulphate reducing bacteria (SRB) reduce sulfate to hydrogen sulphide
(H2S) which is highly toxic and corrosive. The generated H2S causes corrosion of various metals
including stainless steels, copper alloys etc. in oil wells and in the oil-processing system. In
addition, the production of toxic H2S may present a health hazard to the platform personnel
and diminish oil quality by the souring of oil and gas. The aim of this study was to determine the
abundance and distribution of SRB in the reservoirs of Dodan, Garzan and Silivanka Oil Fields.
Petroleum samples were collected from 8 different reservoirs in the Dodan, Garzan and Silivanka
Oil Fields. Two samples from each reservoir were taken and one of them was used for obtaining
water phase of oil. Postgate medium B, with and without salt (NaCl), was used for isolation of
SRB from oil and oil-water phase of the samples. SRB counts in the samples were determined by
the MPN (Most Probable Number-MPN) technique. The culturing was carried out in duplicate
and while one of the series was incubated at 30°C, other series were kept at 55°C for 3 months.
At the end of the incubation period, the growth of SRB was not observed in the oil and oilwater
phase samples taken from Dodan 17M, Dodan 6S and Silivanka 28 oil fields. However, SRB
were especially isolated from oil-water phase samples obtained from Garzan 17, Garzan 89 and
Silivanka 31 oil fields. It was determined that oil-water phase samples of the Garzan 17 oil field,
which were incubated at 30°C, contained a high number of SRB (107 cell/ml). Our results showed
that the number of SRB in the oil-water phase was generally higher than in the oil. In addition, it
was determined that SRB isolates obtained from these oil fields need to salt for their growth and
also they grow better in mesophilic conditions (20°C-45°C).
Keywords: Sulphate reducing bacteria, hydrogen sulfide, biodegradation, oil fields,
microbiologically influenced corrosion
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