Microbiological Corrosion Law and Corrosion Rate Model of Natural Gas Gathering and Transportation Pipeline

In order to investigate the effect of sulfate-reducing bacteria (SRB) on the corrosion behavior of natural gas gathering and transportation pipelines, the corrosion rate of five steel materials at different SRB concentrations and their anti-bacterial corrosion performance under normal-pressure and high-pressure conditions were studied in immersion test. A prediction model of microbial corrosion rate was established based on the experimental results. PIPSIM software was used to simulate the changes of pipeline temperature and pressure to modify the model. The results show that in both normal-pressure and high-pressure environments, the corrosion rates of five steel materials increased with the increase of SRB concentration. N80 steel had the strongest resistance to SRB corrosion. There was an error of 0.06-0.07 mm/a between the corrosion rates calculated by the prediction model and the actual corrosion rates. The modified model could better predict the pipeline microbial corrosion rate.