Biofilm Formation and Corrosion on Carbon Steel API 5LX60 in Clayey Soil

Abstract

Corrosion of buried pipelines is a matter of concern to the oil and gas industry since the time when carbon steel began to be widely used in these pipelines for the transportation of fluids. The microbial communities associated with biofilms promote modification in the surrounding environment and may accentuate the degradation of oil and gas pipelines causing leaks or even accidents. This work aimed to evaluate corrosion and biofilm formation in carbon steel API 5LX60 coupons buried in clayey soil from an industrial region in northeastern Brazil. The average corrosion rates were determined by gravimetric test and the quantification of bacteria and fungi were using the Most Probable Number (MPN) and Colony Forming Units (CFU) techniques respectively. The results showed a great influence of clayey soil on corrosion rates and time of adherence for microorganisms on metal surfaces.

Microbiologically Influenced Corrosion of a Pipeline in a Petrochemical Plant

“…The soil contained some chloride ions as well. Chloride makes the environment more aggressive since it damages the passive oxide film on the surface and causes localized corrosion [2,14].…”

“…Biofilms could host a variety of different microorganisms including fungi, bacteria, eukaryotes, and archaea, with each having a different metabolic ability [2]. The SRB, in particular, has a vigorous metabolism, producing a certain amount of EPS (in fact, often there are also other microorganisms present that are mainly responsible for EPS production), which rapidly adhere to the surface of the metal and build a biofilm [14,18]. The biofilm, in this case, has a porous nature, making the ion/nutrition exchange much easier.…”

Novel, Low Cost and Fast Detection Sensor for Biogenic H2S Gas Based on Polyaniline/ZnO, CdO and CeO2 nanocomposites at Room Temperature

“…Furthermore, SRB have the ability to make a biofilm, this phenomenon happens when the SRB contact with the iron surface especially at low stream flow and acting to mimic the surrounded conditions to protect themself and hence causing more aggressive corrosion media in comparison to their planktonic counterparts. Biofilms can resist the biocide more than 1000 times comparing to their planktonic forms [10]. The development of rapid and effective techniques for the SRB monitoring in natural and industrial environments have great efforts in last decades.…”

Microbiologically-Influenced Corrosion of 1020 Carbon Steel in Artificial Seawater Using Garlic Oil as Natural Biocide

“…Methods for the prevention and control of MIC are necessary to avoid or reduce the effects of microbial activity on metals and alloys, such as carbon steel. Most of the time microorganisms are in the sessile state, thus composing biofilms 5 . Sessile cells, which are attached to the steel surface, are directly responsible for MIC because they can utilize extracellular electrons or secrete highly concentrated corrosive metabolites underneath the biofilms 4,6 .…”