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A Sensitive Visual Method for the Detection of Hydrogen Sulfide Producing Bacteria
Published on: June 27, 2022
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Sulfide Production and Microbial Dynamics in the Water Reinjection System from an Offshore Oil-Producing Platform
Vitória da Silva Pereira Domingues1, Maira Paula de Sousa2, Vinicius Waldow2
1Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro 21941-902, Brazil.
Microorganisms
|January 28, 2026
Summary
Produced water (PW) reinjection in oil recovery can lead to high hydrogen sulfide (H₂S) levels due to sulfate-reducing bacteria (SRB). Flotation treatment for PW is insufficient, potentially enriching SRB in reinjection systems.
Area of Science:
- Microbiology
- Petroleum Engineering
- Environmental Science
Background:
- Oil companies use seawater injection (IH) and produced water (PW) reinjection (PWRI) for enhanced oil recovery.
- PWRI systems and associated water sources (IH, PW) can harbor sulfate-reducing bacteria (SRB), causing oil reservoir souring via hydrogen sulfide (H₂S) production.
- Standard PW treatment involves flotation to remove oil, but its microbial control efficacy is questioned.
Purpose of the Study:
- To evaluate H₂S production and microbial dynamics in IH, PW, and PWRI systems of a Brazilian oil reservoir.
- To assess the effectiveness of flotation treatment on microbial populations, particularly SRB, in PW.
- To identify key microbial groups associated with H₂S production in these oilfield water systems.
Main Methods:
- Hydrogen sulfide (H₂S) concentration measurements.
- Microbial analysis using most probable number (MPN) enumeration.
- Quantitative PCR (qPCR) for targeted SRB detection.
- Amplicon sequencing for comprehensive microbiome profiling.
Main Results:
- PW samples exhibited the highest average H₂S concentrations.
- The H₂S threshold of 2 mg L⁻¹ was exceeded in 18% of PW and 16% of PWRI samples.
- While MPN showed no correlation, qPCR and sequencing identified Desulfobacterota as the dominant SRB in PW and PWRI.
- Flotation treatment demonstrated poor microbial control in PW and led to the enrichment of SRB (Desulfobacterota), Thermotogota, and Proteobacteria in PWRI.
Conclusions:
- PW is a significant source of H₂S, with potential for reservoir souring even after treatment.
- Flotation is inadequate for controlling SRB in PW, potentially exacerbating microbial issues in PWRI systems.
- Microbiome analysis is crucial for understanding SRB dynamics and informing strategies to mitigate H₂S production in oilfield operations.
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