Microbiologically Induced Corrosion Of X80 Pipeline Steel In The Dynamic Oil Produced Water

In this paper,we study the law of the microbial corrosion in medium flow under the actual working conditions and realize the in situ electrochemical test through a loop system which was designed to simulated oil and gas field.The distribution of velocity,shear stress and turbulent vorticity at different positions of the simulated pipeline were calculated by hydrodynamic software CFD.The relationship between the change of biofilm structure and microbial corrosion was established under dynamic shear conditions.The turbulent flow occurs in the pipeline at the flow rate under the experimental condition.when the fluid flows in the pipeline at 2 m/s,3 m/s and 4 m/s,the fluid flow velocity,near-wall shear force and turbulence of the inside elbow obviously reaches the maximum value,while the outside of the elbow reaches minimum value through the CFD simulation.The loop system of pipeline is full of simulated oil produced water in the state of sterile or inoculated SRB.Medium flowed at 2 m/s,3 m/s and 4 m/s after X80 pipeline steel was immersed statically for 3 days.Sterile system,the flow of medium at different flow rates can completely destroy the corrosion product film on metal surface.Inoculated with SRB system,the medium had no obvious damage or peeling at 2 m/s and 3 m/s,and the film had obvious damage or peeling when the medium flow rate increased by 4 m/s.With the increase of the medium flow rate,the damage or peeling degree of the sample layer in each position of the pipeline is increasing.The flow of the medium can significantly promote the corrosion rate of the sample in the sterile system and the inoculated SRB system.When the pipeline medium is filled with saturated CO2,or SRB and saturated CO2 coexist.Medium flowed at 3 m/s,and for 6 hours.Saturated CO2 system,the flow of medium can quickly and completely destroy or strip the corrosion product film on metal surface.Inoculated with SRB saturated CO2 system,the flow of media can gradually destroy or strip the corrosion product film on metal surface.The flow of the medium can destroy the film formed on the metal surface.The flow of the medium can promote the corrosion rate of the sample in the saturated CO2 system and the saturated CO2 system inoculated SRB.The minimum sterilization concentration(MIC)of benzalkonium chloride was 40 ppm.Fungicide can quickly and efficiently kill sulfate-reducing bacteria.As medium flow time goes by at 2 m/s,the corrosion rate of the samples at each position of the pipeline is decreasing.At the same time,the medium flow would promote the benzalkonium chloride adsorbed into the film on the pipeline.