PROSPECTS AND OPPORTUNITIES FOR INCREASING THE CAPACITY FOR NATURAL GAS STORAGE IN UNDERGROUND GAS STORAGE FACILITIES IN THE REPUBLIC OF BULGARIA

ABSTRACT. The article analyses the prospects and opportunities for establishing an underground gas hub on the territory of the Republic of Bulgaria in order to increase natural gas storage capacity. This is related to the well-developed gas transmission pipeline network, the numerous entry points for gas supplies to Bulgaria, and its transit to other countries. A summary classification of underground gas storage facilities is presented, depending on their place of creation. The basic principles for the construction of underground gas storage facilities in depleted hydrocarbon deposits, aquifers, and impermeable rocks are discussed. The distribution of underground gas storage in the European Union is analysed and prospective sites for underground gas storage are recommended.