Conventional Application of Biocides May Lead to Bacterial Cell Injury Rather Than Bacterial Kill Within a Biofilm

Mitigation of microbiological related problems, specifically microbially influenced corrosion (MIC), is often mitigated utilizing biocides or biostatic chemicals.  The use of the chemicals is often employed to control viable bacterial numbers, which would ultimately mitigate microbiological activity.  However, after applying biocides for over 50 years within the petroleum industry, MIC is present and has been implicated in several critical failures.  Although these failures still occur, no work has been done to establish and understand if current treatment regimes are ultimately mitigating MIC by controlling bacteria, specifically SRB’s within a biofilm.  This paper reports the efficacy of biocides applied in a dynamic flow cell system evaluating current conventional treatment regimes decreasing viable bacterial numbers within a biofilm,and thus decreasing SRB activity.  The data suggests that biocides may not be killing bacteria within a biofilm, and after further review of doubling times of SRB’s within the bacterial biofilm, suggests that bacterial cell injury may be a possible result rather than bacterial cell kill Bacteria and Microbiologically Induced Corrosion Control in Unconventional Gas Field