Methodology for Accelerated Microbiologically Influenced Corrosion in Under Deposits from Crude Oil Transmission Pipelines

摘要

The current study presents the progress made in developing a protocol for accelerated microbiologically influenced corrosion (MIC) in under deposits for crude oil transmission pipelines. The methodology incorporates nutrient-rich broths for the cultivation of naturally occurring bacteria obtained from sludge samples and the formation of an active biofilm on the surface of carbon steel metal specimens. The biofilm is then overlain with sludge, exposed to crude oil and an under deposit environment is formed. Using this approach, corrosion rates in excess of 1.5 mm/y have been duplicated with evidence of pitting; more importantly, laboratory testing has shown that these corrosion rates could be decreased with the addition of a biocide and proprietary chemical package injection. Moreover, pilot scale experiments were conducted by forming the biofilm/under deposit environment on the surface of a corrosion probe that was recessed within an oil flow loop. The pilot scale flow loop evaluation showed that the addition of proprietary chemical package alone could dramatically decrease the overall corrosion rate by 83 % within hours and by 95 % in days.