Microbiologically Influenced Corrosion (MIC) is becoming increasingly important, especially to
the oil and gas industry as more and more reservoirs are soured due to increased practice of
water flooding and pipelines are aging (some even beyond their anticipated life expectancies).
Despite the fact that MIC research has been going on for several decades, there is much
confusion in the MIC literature regarding the fundamental mechanisms in MIC. This has greatly
hindered the development of reliable prediction and new mitigation methods. A new MIC
theory entitled Biocatalytic Cathodic Sulfate Reduction (BCSR) theory was presented in
NACE/2009. It sheds some lights on MIC mechanisms. This work demonstrates how the
theory together with bioenergetics, electrochemical kinetics, and mass transfer can be used to
explain various mysteries in MIC. Some experimental data and model simulation results for
MIC due to sulfate reducing bacteria (SRB) and acid producing bacteria (APB) are used in the
explanations.
Keywords: MIC, Model, Mechanism, SRB, APB, Sulfate reduction, Proton reduction, Acid
reduction