Nitrate-Mediated Microbially Enhanced Oil Recovery (N-MEOR) from model upflow bioreactors

Gassara, Fatma; Suri, Navreet; Voordouw, Gerrit

doi:10.1016/j.jhazmat.2015.12.039

Cited by 14 publications

(12 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Oil production using aqueous electron donors, is indicated in Table S3 and has been described elsewhere. 15 In the presence of sufficient molasses, glucose or acetate to reduce 80 mM of nitrate, the average production was 25.0 ± 11.1% of ROIP (N = 5), similar to that obtained with high toluene or high toluene and heptane. a These contained the indicated concentrations of electron donor in the oil phase and of nitrate electron acceptor in the aqueous phase.…”

Section: Environmental Science and Technologysupporting

confidence: 70%

Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors

Gassara

Suri

Stanislav

et al. 2015

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Microbially enhanced oil recovery (MEOR) often involves injection of aqueous molasses and nitrate to stimulate resident or introduced bacteria. Use of light oil components like toluene, as electron donor for nitrate-reducing bacteria (NRB), offers advantages but at 1-2 mM toluene is limiting in many heavy oils. Because addition of toluene to the oil increased reduction of nitrate by NRB, we propose an MEOR technology, in which water amended with light hydrocarbon below the solubility limit (5.6 mM for toluene) is injected to improve the nitrate reduction capacity of the oil along the water flow path, followed by injection of nitrate, other nutrients (e.g., phosphate) and a consortium of NRB, if necessary. Hydrocarbon- and nitrate-mediated MEOR was tested in low- and high-pressure, water-wet sandpack bioreactors with 0.5 pore volumes of residual oil in place (ROIP). Compared to control bioreactors, those with 11-12 mM of toluene in the oil (gained by direct addition or by aqueous injection) and 80 mM of nitrate in the aqueous phase produced 16.5 ± 4.4% of additional ROIP (N = 10). Because toluene is a cheap commodity chemical, HN-MEOR has the potential to be a cost-effective method for additional oil production even in the current low oil price environment.

show abstract

Section: Environmental Science and Technologysupporting

confidence: 70%

Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors

Gassara

Suri

Stanislav

et al. 2015

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…When injecting nitrate in high-toluene reservoir such as PNG, we expect extensive nitrate reduction and formation of high hNRB biomass concentrations ( Table 2 and Figure 3 ). This biomass may be surface-active itself or may produce biosurfactant causing oil emulsification increasing oil recovery (Youssef et al, 2009; Kryachko and Voordouw, 2014; Li et al, 2014; Gassara et al, 2017). Increasing the toluene-content of oil can be done by injecting water-dissolved toluene, which transfers to the oil phase.…”

Section: Discussionmentioning

confidence: 99%

The Effectiveness of Nitrate-Mediated Control of the Oil Field Sulfur Cycle Depends on the Toluene Content of the Oil

Suri

Voordouw

2017

Front. Microbiol.

Self Cite

View full text Add to dashboard Cite

The injection of nitrate is one of the most commonly used technologies to impact the sulfur cycle in subsurface oil fields. Nitrate injection enhances the activity of nitrate-reducing bacteria, which produce nitrite inhibiting sulfate-reducing bacteria (SRB). Subsequent reduction of nitrate to di-nitrogen (N2) alleviates the inhibition of SRB by nitrite. It has been shown for the Medicine Hat Glauconitic C (MHGC) field, that alkylbenzenes especially toluene are important electron donors for the reduction of nitrate to nitrite and N2. However, the rate and extent of reduction of nitrate to nitrite and of nitrite to nitrogen have not been studied for multiple oil fields. Samples of light oil (PNG, CPM, and Tundra), light/heavy oil (Gryphon and Obigbo), and of heavy oil (MHGC) were collected from locations around the world. The maximum concentration of nitrate in the aqueous phase, which could be reduced in microcosms inoculated with MHGC produced water, increased with the toluene concentration in the oil phase. PNG, Gryphon, CPM, Obigbo, MHGC, and Tundra oils had 77, 17, 5.9, 4.0, 2.6, and 0.8 mM toluene, respectively. In incubations with 49 ml of aqueous phase and 1 ml of oil these were able to reduce 22.2, 12.3, 7.9, 4.6, 4.0, and 1.4 mM of nitrate, respectively. Nitrate reduced increased to 35 ± 4 mM upon amendment of all these oils with 570 mM toluene prior to incubation. Souring control by nitrate injection requires that the nitrate is directed toward oxidation of sulfide, not toluene. Hence, the success of nitrate injections will be inversely proportional to the toluene content of the oil. Oil composition is therefore an important determinant of the success of nitrate injection to control souring in a particular field.

show abstract

“…In reality, the contribution of emulsification is likely less, whereas the largest emulsion droplets may also contribute to through flow diversion. Injection of similar sand-packed columns with sufficient aqueous molasses, glucose or acetate to reduce 80 mM of injected nitrate gave production of 14, 11 and 18% of ROIP, respectively, under low pressure (1 atm) conditions (Gassara et al, 2017). Hence, hydrocarbon- and nitrate-mediated MEOR is similarly effective as carbohydrate- and nitrate-mediated MEOR, which likely involves a different mechanism that does not involve attachment of cells to oil, e.g., through biosurfactants (Okpokwasili and Ibiene, 2006; Youssef et al, 2007; Safdel et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

Microbially Enhanced Oil Recovery by Alkylbenzene-Oxidizing Nitrate-Reducing Bacteria

et al. 2019

Self Cite

View full text Add to dashboard Cite

Microbially enhanced oil recovery (MEOR) of heavy oil and bitumen is challenging because light hydrocarbons, which can feed resident microbial communities are present in low concentrations, if at all. We have recently shown that increasing the toluene concentration of heavy oil by aqueous injection followed by injection of nitrate boosts the activity of toluene-oxidizing nitrate-reducing bacteria in heavy oil-containing sand pack columns, giving production of residual oil in place (ROIP). In the current work we found that ethylbenzene is as effective as toluene. Microbial community analyses indicated Thauera and Pseudomonas to be main components of nitrate-containing batch and continuous cultures, regardless whether ethylbenzene or toluene was used as the electron donor. Biomass from batch cultures grown with heavy oil amended with ethylbenzene or toluene and nitrate or biomass from continuous cultures grown on ethylbenzene or toluene and nitrate had similar MEOR activity. Increasing the concentration of injected biomass from continuous cultures increased the fraction of ROIP recovered both in the absence and in the presence of nitrate. Nitrate increased the fraction of ROIP recovered by about 2-fold by increasing the concentration of biomass in the columns. Emulsification of oil by surface-adhering biomass and blocking of aqueous flow channels by oil emulsion droplets are proposed as a possible mechanism of hydrocarbon- and nitrate-mediated MEOR. Pure isolates Thauera sp. NS1 and Pseudomonas sp. NS2, which used both ethylbenzene and toluene, were obtained but did not offer improved MEOR compared to the use of batch and continuous cultures.

show abstract

Nitrate-Mediated Microbially Enhanced Oil Recovery (N-MEOR) from model upflow bioreactors

Cited by 14 publications

References 13 publications

Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors

Microbially Enhanced Oil Recovery by Sequential Injection of Light Hydrocarbon and Nitrate in Low- And High-Pressure Bioreactors

The Effectiveness of Nitrate-Mediated Control of the Oil Field Sulfur Cycle Depends on the Toluene Content of the Oil

Microbially Enhanced Oil Recovery by Alkylbenzene-Oxidizing Nitrate-Reducing Bacteria

Contact Info

Product

Resources

About