Development of microbially influenced corrosion on carbon steel in a simulated water injection system

Abstract

Microbially influenced corrosion (MIC) on internal pipeline surfaces has become a severe problem during the water injection process in secondary oil recovery. The formation of a biofilm, normally dominated by sulfate-reducing bacteria (SRB), is believed to be the critical step of the MIC process. A continuously fed biofilm simulating the water injection process was operated to investigate the influence of biofilm development on MIC behavior in the early phase of corrosion development. The development of the corrosion product film and biofilm was monitored for 5 months with electrochemical impedance spectroscopy, linear polarization resistance, scanning electron microscopy, 3D optical profiling, and direct weight measurement. MIC development was found to comprise three phases: initialization, transition, and stabilization. The initialization phase involved the formation of the corrosion product layer and the initial attachment of the sessile microbes on metal surface. In the transition phase, the MIC process gradually shifted from charge-transfer-controlled reaction to diffusion-controlled reaction. The stabilization phase featured mature and compact biofilm on the metal surface, and the general corrosion rate (CR) decreased due to the diffusional effect, while the pitting CR was enhanced at a lower carbon source level, which supported the mechanism of direct electron uptake from the metal surface by SRB.

Corrosion resistance and corrosion behavior of high‐copper‐bearing steel in marine environments

“…[ 8 ] Therefore, marine engineering steels are required to possess both corrosion‐resistant and antifouling properties. [ 9–12 ]…”

Understanding and control of microbially influenced corrosion in simulated oilfield seawater injection systems

“…Both pitting depth plots (Figure 6-3g) and pitting corrosion rate diagrams (Figure 6-3h)showed that the pitting corrosion accelerated from Day 326 in Control, which indicated that microbes tended to attack subtle areas that were previously corroded on the metal surface. As shown in our previous study, a dense and compact biofilm formed on the coupon surface could be a barrier for the transfer of carbon substrates from the bulk liquid phase to deep layers of the biofilm(Zhong et al 2019). The diffusion limitation likely caused low carbon concentrations at the bottom of the biofilm (i.e.…”

“…First of all, H2S produced by SRB could directly interact with iron, inducing the anodic reaction of iron dissolution (Bai et al 2015). SRB could also extract electrons directly from Fe 0 , especially when associated with low carbon levels, which would cause pitting corrosion underneath the biofilm (Gu et al 2009, Zhong et al 2019. Further, the metal acts as an electrode submerged in the electrolyte, thus the corrosion process is also influenced by many other ions, such as chloride, in the medium.…”