The process of biocorrosion of pipelines develops as a result of the influence of various factors. The process of adaptation of microorganisms to the action of individual environmental factors is quite complex and is determined by a set of parameters. The soil conditions of the pipeline route lead to active bacterial and mycological colonization. Micromycetes that are part of the microbial association can change the concentration of individual bacteria, producing antibiotic compounds, thereby changing the quantitative ratios between various representatives of the microbiocenosis. Purpose of the work was to investigate the complex of factors that make up the development of the biocorrosion process on the routes of the oil pipeline. The factors of development of corrosion are studied in the samples of soil on the routes of the oil pipeline and in control samples. Bacteriological study of soil samples made it possible to establish the qualitative and quantitative characteristics of corrosive microorganisms - sulfate-reducing and thionic bacteria. The quantitative characteristics of the identified thionic and sulfate-reducing bacteria in the pipeline route and in the control samples differed. The mycological study of the soil showed a higher quantitative content of micromycetes near the oil pipeline in comparison with the control soil samples. The level of the index of specific electrical resistance of the soil has been established, indicating the high corrosiveness of the soil and the optimal indicator of moisture for the maximum rate of underground soil corrosion. The obtained results indicate the formation of a specific soil microbiocenosis on the oil pipeline routes, represented by corrosive microorganisms - bacteria, fungi that contribute to the development of biocorrosion. The analysis of the severity of the microbiological indicators of the soil indicates the need to introduce additional research methods in order to further identify the spectrum of corrosive microorganisms that cause the development of corrosion along the oil pipeline routes.
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