Testy biocydów i neutralizatorów H2S jako dodatków do płuczek wiertniczych i płynów szczelinujących

Abstract

The article presents the results of studies on substances with a biocidal effect in terms of their possible use as additives to drilling muds and fracturing fluids. The aim of the work was to identify the most effective biocides by examining their action on aerobic and anaerobic bacteria, fungi, sulfate-reducing bacteria (SRB), and a consortium of microorganisms. Various chemicals have been considered, due to a constant and overriding goal to find the one with the highest activity, and above all, the ones that have not yet been tested. Particular attention was paid to substances that, apart from known biocidal properties, have also the ability to neutralize hydrogen sulfide, and to reduced sulfur compounds (H2S scavengers), and the so-called “green biocides”, i.e. those that are considered safe for the environment. Most of the tested biocidal agents were effective against aerobic and anaerobic bacteria, while 10 out of 12 showed good or very good activity against SRB (low MIC and MBC values), including 3 out of 4 H2S scavengers. On the other hand, only some biocidal agents proved to be effective against fungi and microbial consortium; among them were agents containing quaternary ammonium compounds (Bardac LF and Barquat CB-80), triazine derivatives (Biostat and Petrosweet HSW 82165) and DBNPA (Biopol C-103L). Bardac LF and Barquat CB-80, together with the mixture of Grotan OX and Preventol GDA 50, upon introduction to the drilling mud and fracturing fluid, were superior over other biocidal agents (Biostat, Petrosweet HSW 82165 and Biopol C-103L), showing the full activity at 800 ppm. Environmentally friendly biocide Aquacar THPS 75 appeared to be the least effective.

Laboratory tests on the use of Thiobacillus and Acidihiobacillus species in the process of eliminating H2S from formation waters and process waters

“…In the past, purifying water from hydrogen sulphide entailed a number of technological difficulties, resulting from the chemical nature of hydrogen sulphide. Currently, there are many methods for removing hydrogen sulphide and acid gasses from natural and shale gas (Schieman, 1999;Salma et al, 2001;Abishek, 2006;Mokhatab et al, 2015;Kapusta et al, 2021;Weiland and Hatcher, 2021).…”