The effect of long-term nitrate treatment on SRB activity,corrosion rate and bacterial community composition in offshore water injection systems |
| |
Authors: | Gunhild Bødtker Tore Thorstenson Bente-Lise P Lillebø Bente E Thorbjørnsen Rikke Helen Ulvøen Egil Sunde Terje Torsvik |
| |
Institution: | (1) Unifob Petroleum, Allégaten 41, 5007 Bergen, Norway;(2) StatoilHydro, Sandslihaugen 30, 5254 Bergen, Norway;(3) StatoilHydro, Forusbeen 50, 4035 Stavanger, Norway;(4) Centre for Integrated Petroleum Research (CIPR), Allégaten 41, 5007 Bergen, Norway;(5) Unifob Petroleum, Jahnebakken 5, 5020 Bergen, Norway |
| |
Abstract: | Biogenic production of hydrogen sulphide (H2S) is a problem for the oil industry as it leads to corrosion and reservoir souring. Continuous injection of a low nitrate
concentration (0.25–0.33 mM) replaced glutaraldehyde as corrosion and souring control at the Veslefrikk and Gullfaks oil field
(North Sea) in 1999. The response to nitrate treatment was a rapid reduction in number and activity of sulphate-reducing bacteria
(SRB) in the water injection system biofilm at both fields. The present long-term study shows that SRB activity has remained
low at ≤0.3 and ≤0.9 μg H2S/cm2/day at Veslefrikk and Gullfaks respectively, during the 7–8 years with continuous nitrate injection. At Veslefrikk, 16S rRNA
gene based community analysis by PCR–DGGE showed that bacteria affiliated to nitrate-reducing sulphide-oxidizing Sulfurimonas (NR–SOB) formed major populations at the injection well head throughout the treatment period. Downstream of deaerator the
presence of Sulfurimonas like bacteria was less pronounced, and were no longer observed 40 months into the treatment period. The biofilm community
during nitrate treatment was highly diverse and relative stable for long periods of time. At the Gullfaks field, a reduction
in corrosion of up to 40% was observed after switch to nitrate treatment. The present study show that nitrate injection may
provide a stable long-term inhibition of SRB in sea water injection systems, and that corrosion may be significantly reduced
when compared to traditional biocide treatment. |
| |
Keywords: | Nitrate treatment Nitrate-reducing bacteria Sulphate-reducing bacteria Biofilm community composition Corrosion |
本文献已被 PubMed SpringerLink 等数据库收录! |
|