Background. Two thirds of all oil reserves of the Russian Federation are concentrated on the territory of Western Siberia. Field work, production and distribution of petroleum products at the oil and gas field are the main reasons for the negative impact on the ecosystems of the northern territories. Purpose. The purpose of this study is to evaluate the chemical pollution dynamics of the rivers’ bottom sediments in the Middle Ob region, the region of the Samotlor field. Materials and methods. Based on the chemical analysis of the sediment samples, concentrations and total values of the following chemical elements were determined: manganese, copper, nickel, lead, chromium, zinc, iron sulfate ions, chloride ions, petroleum products, mercury. Based on the results of long-term studies of the chemical analysis dynamics of the bottom sediments in the Ob, Agan, and Vakh rivers, a correlation and regression analysis of the studied indicators was carried out. Results. The results of the correlation analysis suggest the existence of negative and positive correlations in the studied indicators. Regression analysis of the migration of chemical elements in sediment samples during the study period shows significant fluctuations in the total concentration of chemical elements in sediments, but there is a general tendency to decrease their concentration in sediments. Conclusion. Analyzing the ecological state of the studied rivers by the quality of bottom sediments, in general, we can conclude that they are in stable condition. During the study period, there has been a positive dynamics in the concentration of chemical elements in bottom sediments.