Sustainable use of natural resources is an integral part of economic and energy safety of any country. On the back of development of conventional oil and gas reserves, especial attention shall be paid to exploration and development of alternative sources of fuel. Coal gas can be utilized as one of such reserves and in some case it can be utilized as an individual raw material during development of coal deposits. Assessment of quality of hydrocarbon gases accumulated in form formations and sources of their origin (methane content) is vitally important for selection of prospective sections for long-term production of hydrocarbons. The above problems may be successfully solved by means of geochemical methods based on research of isotope relations of carbon in coal, carbon dioxide, and methane.