European MIC Network Biocorrosion Webinars, 26th May and 2nd June 2020
European MIC Network – 2 free webinars
The format will be a short introduction to the speaker, 30 min technical presentation on MIC, 20 min of Q&A and wrap-up and announcements.
Tuesday 26th May at 15.00 (CEST)
Microbiologically Influenced Corrosion on Offshore Oil Recovery Platforms in Response to Various Nitrate and Nitrite Injection Chemistries – Danika Nicoletti and Lisa M. Gieg from the University of Calgary.
The risk of microbiologically influenced corrosion (MIC) on the topside equipment of Floating, Production, Storage, and Offloading (FPSO) crude oil recovery vessels under conditions of nitrate- or nitrite-mediated souring control is poorly understood. This study aimed to understand the microbial response and corrosive impact of topside produced water samples from two FPSOs under various nitrate and nitrite chemistries in long-term, high-temperature microcosm experiments incubated with carbon steel corrosion coupons.
A combination of microbial community, chemical, and corrosion analyses were used in concert to assess the corrosion risk of offshore produced water samples. A 5 mM nitrate treatment was found to be more effective in sulfate reduction inhibition in samples collected from one FPSO compared to the other, however a 5 mM nitrite treatment was the most effective on samples from both FPSOs with regards to sulfate reduction inhibition. The nitrite treatment, however, was also found to confer general corrosion rates of up to 0.08 mm/year. Corrosion coupons that experienced the most severe general corrosion rates, up to 0.48 mm/year, had no nitrate nor nitrite treatment applied. The results of this work prompts a recommendation for operators to assess FPSOs individually for their MIC risk related to nitrate and nitrite injection treatments.
Tuesday 2nd June at 15.00 (CEST)
Application of X-Ray Absorption Near Edge Structure (XANES) spectroscopy and electrochemistry to study MIC – a snapshot via the story of bacteria born to corrode – Nina Wurzler, Jan David Schutter, Matthias Dimper and Ozlem Ozcan from BAM and Ralph Wagner and dirk Lützenkirchen Hecht from the University of Wuppertal.
Microbiologically influenced corrosion of stainless steel is a growing concern for diverse industrial applications. Stainless steel is protected from corrosion by the formation of a passive layer containing mainly chromium and iron oxides. Electroactive metal reducing bacteria (MRB) can utilize these chromium and iron oxides and hydroxides as electron acceptors.
The aim of this work is to understand the mechanisms and kinetics of the MRB-induced transformation processes within the passive film. Therefore, the biofilm formation and corrosive properties of the biofilms were characterized by means of open circuit potential monitoring and electrochemical impedance spectroscopy (EIS). As imaging technique Scanning Electron Microscopy (SEM) has been used to compare the biofilm structure and surface coverage. Additionally, X-ray Absorption techniques were used for the characterization of the oxide chemistry before and after incubation with microbes. Two setups were implemented for ex situ analysis of steel surfaces as well as in situ measurements on model Fe-films to complementing the results from surface chemistry with kinetic information. Furthermore, they deliver two different measurement signals, grazing incidence reflection and backscattered fluorescence; each with their own advantages for the analysis of MIC processes.
The presentation will summarize our results regarding the effects of MRB’s cultivation conditions on their chemical/electrochemical interaction mechanisms with stainless steel surfaces. XANES in situ technique combined with monitoring of electrochemical processes provide useful insights from a fundamental point of view for the development of novel mitigation strategies for microbiologically influenced corrosion.
If you would like to attend either of these webinars please send an email to firstname.lastname@example.org to be added to the distribution and invitation list.
Slides from the talks and more information can be found here.