Hydrogen sulfide (H2S) generation by sulfur-compound reducing microbes is one of the central drivers of microbiologically influenced corrosion (MIC). MIC presents significant risk to operators and infrastructure in many industries, including those involved in oil and gas production. Because of its corrosivity, toxicity to humans, and its ability to devalue produced fluids and gas, H2S is particularly undesirable in the oilfield. Microbial growth can occur throughout oil and gas production systems, but high levels of H2S are often associated with growth of sulfide-producing bacteria and archaea within the reservoir itself, resulting in souring of the produced fluids and gas. A number of chemistries intended to prevent microbial H2S generation have been studied for their efficacy against sulfide-producing oilfield microbes, with varying degrees of success. To this end, a new class of compounds has recently been introduced that have been shown to be extremely effective at inhibiting sulphidogenesis at extremely low dosages in both bottle tests and continuously fed bioreactors. In the work presented herein, two additional classes of sulphidogenesis inhibitory chemistries are introduced and the impact of these three classes of molecules against MIC, as well as H2S generation, is considered. Altogether, this work shows the continued potential for discovery of novel sulphidogenesis-inhibitory compounds as well as the recent gains made towards decreasing the impact of H2S production and on MIC as a whole.
Key words: sulfate-reducing bacteria, microbiologically influenced corrosion, MIC, hydrogen sulfide, H2S, reservoir souring, biocide