Título:	Effects of nitrate injection on microbial enhanced oil recovery and oilfield reservoir souring.
Autoria:	SILVA, M. L. B. da SOARES, H. M. FURIGO JÚNIOR, A. SCHMIDELL, W. CORSEIUL, H. X.
Afiliação:	MARCIO LUIS BUSI DA SILVA, CNPSA; HUGO MOREIRA SOARES, UFSC; AGENOR FURIGO JÚNIOR, UFSC; WILLIBALDO SCHMIDELL, UFSC; HENRY XAVIER CORSEIUL, UFSC.
Ano de publicação:	2014
Referência:	Applied Biochemistry and Biotechnology, v. 174, n. 5, p. 1810-1821, 2014.
Conteúdo:	Column experiments were utilized to investigate the effects of nitrate injection on sulfate-reducing bacteria (SRB) inhibition and microbial enhanced oil recovery (MEOR). An indigenous microbial consortium collected from the produced water of a Brazilian offshore field was used as inoculum. The presence of 150 mg/L volatile fatty acids (VFA´s) in the injection water contributed to a high biological electron acceptors demand and the establishment of anaerobic sulfate-reducing conditions. Continuous injection of nitrate (up to 25 mg/L) for 90 days did not inhibit souring. Contrariwise, in nitrogen-limiting conditions, the addition of nitrate stimulated the proliferation of ?-Proteobacteria (including SRB) and the associated sulfide concentration. Denitrification-specific nirK or nirS genes were not detected. A sharp decrease in water interfacial tension (from 20.8 to 14.5 mN/m) observed concomitantly with nitrate consumption and increased oil recovery (4.3 % v/v) demonstrated the benefits of nitrate injection on MEOR. Overall, the results support the notion that the addition of nitrate, at this particular oil reservoir, can benefit MEOR by stimulating the proliferation of fortuitous biosurfactant-producing bacteria. Higher nitrate concentrations exceeding the stoichiometric volatile fatty acid (VFA) biodegradation demands and/or the use of alternative biogenic souring control strategies may be necessary to warrant effective SRB inhibition down gradient from the injection wells.
Thesagro:	Nitrato Meio ambiente Impacto ambiental Resíduo químico Óleo Biotecnologia
NAL Thesaurus:	Oil fields Environmental impact Chemical residues Biodegradation
Palavras-chave:	Nitrate
Digital Object Identifier:	10.1007/s12010-014-1161-2
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CNPSA)