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Category: Applied and Industrial Microbiology; Environmental Microbiology
Microbial Control of Hydrogen Sulfide Production in Oil Reservoirs, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555817589/9781555813277_Chap10-1.gif /docserver/preview/fulltext/10.1128/9781555817589/9781555813277_Chap10-2.gifAbstract:
Reservoir souring is experienced in most fields flooded with water containing sulfate. The principle in nitrate treatment is to promote an acceptable microbial population of nitrate-reducing bacteria (NRB) at the expense of the unwanted sulfate-reducing bacteria (SRB) population. Water injection into oil reservoirs would be expected to radically change the conditions for the microbes in that environment. The environment close to the injection well will therefore be different from the environment deeper in the reservoir. SRB growing on hexadecane in pure cultures can produce close to 680 mg of hydrogen sulfide (H2S)/liter before sulfide becomes inhibitory. The main modification from the published version is the incorporation of the observed relatively low potential for H2S generation. The biofilm model is supported by field observations. In a recent study, treatment with 0.5 mM nitrate resulted in complete inhibition of SRB activity. The existing biocide injection pumps can normally handle the required nitrate volumes, but on most platforms additional storage capacity must be made available. This can be achieved by installing a new tank or by dedicating an old completion tank, for example, to the nitrate brine. The chemical storage area is now free from the irritating and potentially carcinogenic fumes of conventional biocides.
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The reservoir souring model.
The reservoir souring model.
Development of H2S in a producer.
Development of H2S in a producer.
H2S production in a reservoir model column. The column was treated with 0.5mM nitrate in three periods, from day 188 to 278, day 524 to 763, and day 1487 to 1896. The medium was spiked with 3 mM sulfide from day 1381 to 1425. H2S production from the column is shown by the curve connecting the data points represented by dots. Nitrate treatments are shown by a thick line.
H2S production in a reservoir model column. The column was treated with 0.5mM nitrate in three periods, from day 188 to 278, day 524 to 763, and day 1487 to 1896. The medium was spiked with 3 mM sulfide from day 1381 to 1425. H2S production from the column is shown by the curve connecting the data points represented by dots. Nitrate treatments are shown by a thick line.
Sulfide production profiles along the reservoir model column. Water samples were taken from the column at 10-cm intervals for sulfide determination. Sulfide was measured over a period of 80 days from day 2077 to 2146. Sulfide was measured as described by Cord-Ruwisch (1985).
Sulfide production profiles along the reservoir model column. Water samples were taken from the column at 10-cm intervals for sulfide determination. Sulfide was measured over a period of 80 days from day 2077 to 2146. Sulfide was measured as described by Cord-Ruwisch (1985).
Number of bacteria in biofilm collected from biocoupons mounted downstream of the deaeration tower at Gullfaks C. Hatched bars, SRB quantified with fluorescent antibodies developed specifically against the SRB strains growing in the water injection system at Gullfaks; black bars, viable SRB counts with a medium as described by Postgate (1984) and as recommended by the American Petroleum Institute (1975) ; white bars, viable counts of NRB as described by Myhr et al. (2002) . Viable NRB counts were not measured in June 2000. The black solid line shows the total number of bacteria determined with an epifluorescence microscope after staining with the fluorescent dye DAPI (4',6'-diamidino-2-phenylindole), as described by Porter and Feig (1980) .
Number of bacteria in biofilm collected from biocoupons mounted downstream of the deaeration tower at Gullfaks C. Hatched bars, SRB quantified with fluorescent antibodies developed specifically against the SRB strains growing in the water injection system at Gullfaks; black bars, viable SRB counts with a medium as described by Postgate (1984) and as recommended by the American Petroleum Institute (1975) ; white bars, viable counts of NRB as described by Myhr et al. (2002) . Viable NRB counts were not measured in June 2000. The black solid line shows the total number of bacteria determined with an epifluorescence microscope after staining with the fluorescent dye DAPI (4',6'-diamidino-2-phenylindole), as described by Porter and Feig (1980) .
Average theoretical and measured H2S concentration from 11 Gullfaks C producers.
Average theoretical and measured H2S concentration from 11 Gullfaks C producers.
Growth of indigenous microbes in formation water sampled under pressure
Growth of indigenous microbes in formation water sampled under pressure