Chiren underground gas storage (Chiren UGS) is located close to the city of Vratsa and is being used for covering of the seasonal fluctiations of natural gas consumption in the country.

The storage operates by means of 24 exploitation wells, compressor station with a total installed capacity of 10 MW and other technological units necessary for the ensuring of the injection and withdrawal as well as for the quality of the stored gas.

The daily capacities of the storage depend on the current formation pressure in the gas reservoir as well as on other factors and vary from 0.5 mcm/d up to 4.7 mcm/d. ​​*

Capacity Injection Withdrawal
Max daily capacity 3.2 mcm/d 3.82 mcm/d
Min daily capacity 0.5 mcm/d 0.5 mcm/d


* Maximal daily capacity that depends on formation pressure attainable for a short period of time (≤ 1 month) at forced regimes during crises situations.

Withdrawal curve

Injection curve