Despite the modern trends for the decarbonization of power engineering, transportation, and industry, fossil fuels remain in high demand. On the other hand, the gas and oil industries are also interested in energy efficiency and reduced environmental impact. Drilling of the wells is one of the most environmental danger processes, and reducing the number of wells is an important task that also provides an increase in the overall energy efficiency of the oil/gas mining technological process. Deposit exploration is a necessary part of the petroleum mining industry that determines the presence of fuel resources. The reliable and fast identification of the oil/gas deposits allows for a decrease in the number of drilled research holes. The authors of this article investigated the depth distribution of the hydrocarbon and non-hydrocarbon components of dispersed gas sampled from the cores of West Siberia shallow wells to quickly refine the boundaries of the layers using a priori information in the form of geochemical correlation. The correlations were established based on the amount of methane, the sum of homologs of methane, hydrogen, and olefines. The results show a decrease in the concentrations of gas components at the boundaries of layers with different lithologies. The term "geochemical seal" is introduced to describe such a phenomenon.