Microbial communities succession post to polymer flood demonstrate a role in enhanced oil recovery

Sandeep Rellegadla; Ganshyam Prajapat; Shikha Jain; Akhil Agrawal

doi:10.1007/s00253-023-12673-3

Microbial communities succession post to polymer flood demonstrate a role in enhanced oil recovery

Appl Microbiol Biotechnol. 2023 Sep;107(17):5531-5544. doi: 10.1007/s00253-023-12673-3. Epub 2023 Jul 10.

Authors

Sandeep Rellegadla^{1

2}, Ganshyam Prajapat³, Shikha Jain⁴, Akhil Agrawal⁵

Affiliations

¹ Energy and Environment Research Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandersindri, Kishangarh, Ajmer, Rajasthan, 305817, India.
² Centre for Water Technology, Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000, Aarhus C, Denmark.
³ The Energy and Resources Institute (TERI), Darbari Seth Block, India Habitat Centre, Lodhi Road, New Delhi, 110003, India.
⁴ Enercosm Pvt. Ltd., Jaipur, Rajasthan, 302019, India.
⁵ Energy and Environment Research Laboratory, Department of Microbiology, Central University of Rajasthan, NH-8, Bandersindri, Kishangarh, Ajmer, Rajasthan, 305817, India. akhilagrawal@curaj.ac.in.

PMID: 37428189
DOI: 10.1007/s00253-023-12673-3

Abstract

The role of indigenous microbial communities in residual oil extraction following a recovery process is not well understood. This study investigated the dynamics of resident microbial communities in oil-field simulating sand pack bioreactors after the polymer flooding stage resumed with waterflooding and explored their contribution to the oil extraction process. The microbial community succession was studied through high-throughput sequencing of 16S rRNA genes. The results revealed alternating dominance of minority populations, including Dietzia sps., Acinetobacter sps., Soehngenia sps., and Paracoccus sps., in each bioreactor following the flooding process. Additionally, the post-polymer waterflooding stage led to higher oil recovery, with hydroxyethylcellulose, tragacanth gum, and partially hydrolyzed polyacrylamide polymer-treated bioreactors yielding additional recovery of 4.36%, 5.39%, and 3.90% residual oil in place, respectively. The dominant microbial communities were previously reported to synthesize biosurfactants and emulsifiers, as well as degrade and utilize hydrocarbons, indicating their role in aiding the recovery process. However, the correlation analysis of the most abundant taxa showed that some species were more positively correlated with the oil recovery process, while others acted as competitors for the carbon source. The study also found that higher biomass favored the plugging of high permeability zones in the reservoir, facilitating the dislodging of crude oil in new channels. In conclusion, this study suggests that microbial populations significantly shift upon polymer treatment and contribute synergistically to the oil recovery process depending on the characteristics of the polymers injected. KEY POINTS: • Post-polymer flooded microbial ecology shows unique indigenous microbial consortia. • Injected polymers are observed to act as enrichment substrates by resident communities. • The first study to show successive oil recovery stage post-polymer flood without external influence.

Keywords: Crude oil; Enhanced oil recovery; Microbial communities; Oil field simulating bioreactors; Polymer flooding.

Abstract

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