Combined gases are subdivided into two groups: natural and artificial, and natural gases are divided into three groups:
• Gases extracted from pure gas fields;
• Gas mixtures of methane with petroleum and ethane, propane and butane fractions;
• Gases extracted from gas-condensate deposits.
In nature, pure gases, without impurities, almost do not meet. Impurities in natural gas are most often: hydrogen sulphide, nitrogen, carbon dioxide, water vapor.
Gases extracted from pure gas fields consist mainly of methane.
Natural gases have formed as a result of the decomposition of organic residues of plant and animal origin.
Natural gas, which is used in Bulgaria, is imported from Russia and is mainly extracted from the Tyumenko field in Russia. Since August 1992, the locality near the village of Aglen, Lovech district is included in the main gas pipeline. In 2004, is included the deposit at cape Galata, Varna district. Besides these, on the territory of Bulgaria there are small deposits of local importance - Balgarevo village, Devetaki village, Bardarski Geran village.







Applicable in all areas of industry and everyday life;