The influence of nitrate on microbial processes in oil industry production waters

Abstract

Sulfide accumulation due to bacterial sulfate reduction is responsible for a number of serious problems in the oil industry. Among the strategies to control the activity of sulfate-reducing bacteria (SRB) is the use of nitrate, which can exhibit a variety of effects. We investigated the relevance of this approach to souring oil fields in Oklahoma and Alberta in which water flooding is used to enhance oil recovery. SRB and nitrate-reducing bacteria (NRB) were enumerated in produced waters from both oil fields. In the Oklahoma field, the rates of sulfate reduction ranged from 0.05 to 0.16 microM S day(-1) at the wellheads, and an order of magnitude higher at the oil-water separator. Sulfide production was greatest in the water storage tanks in the Alberta field. Microbial counts alone did not accurately reflect the potential for microbial activities. The majority of the sulfide production appeared to occur after the oil was pumped aboveground, rather than in the reservoir. Laboratory experiments showed that adding 5 and 10 mM nitrate to produced waters from the Oklahoma and Alberta oil fields, respectively, decreased the sulfide content to negligible levels and increased the numbers of NRB. This work suggests that sulfate reduction control measures can be concentrated on aboveground facilities, which will decrease the amount of sulfide reinjected into reservoirs during the disposal of oil field production waters.

Impact of elevated nitrate on sulfate-reducing bacteria: a comparative Study of Desulfovibrio vulgaris

“…The initiation of nitrite stress responses upon exposure to nitrate in D. vulgaris could be of particular ecological significance in the persistence of SRB in environments with elevated levels of nitrate, which has been shown to effectively inhibit SRB populations in the environment (Jenneman et al, 1986;Davidova et al, 2001). More importantly, the nitrate inhibition of SRB is shown to be caused by nitrite, a key intermediate during microbial nitrate reduction (Greene et al, 2003;Voordouw et al, 2009).…”

“…One such factor is the high nitrate concentration of many contaminated sites at the US nuclear weapon complexes managed by the Department of Energy (Riley and Zachara, 1992;NABIR, 2003). The presence of nitrate may pose a specific stress to SRB as nitrate has been observed to suppress sulfate reduction activity in situ (Jenneman et al, 1986;Davidova et al, 2001). Thus, it is important to examine the responses of sulfate-reducing microorganisms in metabolic and regulatory pathways following nitrate exposure to understand their defense mechanisms.…”

Perlindungan Biokakisan Keluli Karbon akibat Bakteria Penurun Sulfat yang Dipencil daripada Minyak Mentah Tropika

“…Bahan perencat lebih tertumpu kepada perlindungan permukaan dalaman keluli, manakala biosid digunakan bagi mengawal aktiviti SRB dan pembentukan biofilem. Glutaraldehid dan nitrit adalah antara biosid yang telah lama digunakan bagi mengatasi pembentukan biofilem SRB (Davidova et al 2001;Gardner & Stewart 2002). Sebahagian penggunaan biosid oleh Industri Minyak dan Petrokimia disenaraikan dalam kajian literatur Yemashova et al (2007).…”

Addition of nitrate for odor control in sewer networks: laboratory and field experiments

“…Hydrogen sulphide is affiliated with corrosion of metal and cement pipes [1], operational problems in wastewater treatment plants (WWTP) [2], as well as with hygiene and odor problems [3]. Among others chemicals inhibiting H 2 S formation or removing sulphide from wastewater such as oxygen, hydrogen peroxide and ferric salts, addition of nitrate seems a promising technique when applied to fields like oil industries -to avoid oil souring or precipitation of metal sulphide in reservoirs [4], [5] -and sewer systems for odor control. Enterprises for drainage in Greece have to deal effectively with urban odor problems originating from sewer systems, especially during summer when tourist season reaches its peak.…”