The impact of bacterial diversity on resistance to biocides in oilfields

Gabriela Feix Pereira,Harry Luiz Pilz-Junior,Gertrudes Corção

doi:10.1038/s41598-021-02494-7

Abstract

Extreme conditions and the availability of determinate substrates in oil fields promote the growth of a specific microbiome. Sulfate-reducing bacteria (SRB) and acid-producing bacteria (APB) are usually found in these places and can harm important processes due to increases in corrosion rates, biofouling and reservoir biosouring. Biocides such as glutaraldehyde, dibromo-nitrilopropionamide (DBNPA), tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and alkyl dimethyl benzyl ammonium chloride (ADBAC) are commonly used in oil fields to mitigate uncontrolled microbial growth. The aim of this work was to evaluate the differences among microbiome compositions and their resistance to standard biocides in four different Brazilian produced water samples, two from a Southeast Brazil offshore oil field and two from different Northeast Brazil onshore oil fields. Microbiome evaluations were carried out through 16S rRNA amplicon sequencing. To evaluate the biocidal resistance, the Minimum Inhibitory Concentration (MIC) of the standard biocides were analyzed using enriched consortia of SRB and APB from the produced water samples. The data showed important differences in terms of taxonomy but similar functional characterization, indicating the high diversity of the microbiomes. The APB and SRB consortia demonstrated varying resistance levels against the biocides. These results will help to customize biocidal treatments in oil fields.

Highlights

Extreme conditions and the availability of determinate substrates in oil fields promote the growth of a specific microbiome
Among the most employed biocides worldwide used in produced water treatment are glutaraldehyde (27% of the market share), dibromo-nitrilopropionamide (DBNPA; 24% of the market share), tetrakis phosphonium sulfate (THPS; 9% of the market share) and alkyl dimethyl benzyl ammonium chloride (ADBAC; 3% of the market share)[3]
The Minimum Inhibitory Concentration (MIC) of glutaraldehyde, DBNPA, tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and ADBAC against sulfate-reducing bacteria (SRB) and acid-producing bacteria (APB) consortia obtained from produced water samples were determined

Summary

Introduction

Extreme conditions and the availability of determinate substrates in oil fields promote the growth of a specific microbiome. Sulfate-reducing bacteria (SRB) and acid-producing bacteria (APB) are usually found in these places and can harm important processes due to increases in corrosion rates, biofouling and reservoir biosouring. Biocides such as glutaraldehyde, dibromo-nitrilopropionamide (DBNPA), tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and alkyl dimethyl benzyl ammonium chloride (ADBAC) are commonly used in oil fields to mitigate uncontrolled microbial growth. The application of similar treatments over the years without technical monitoring selects those microorganisms with high biocide resistance levels[7] Factors such as microbiome composition, treatment history and resistance level need to be observed to choose the best method for microbial control. The Minimum Inhibitory Concentration (MIC) of glutaraldehyde, DBNPA, THPS and ADBAC against SRB and APB consortia obtained from produced water samples were determined

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