Natural Gas Stocks Injection in Bulgaria increased to 22.13 GWh/d on Monday June 15 from 0 in the previous day. Natural Gas Stocks Injection in Bulgaria averaged 9.51 GWh/d from 2011 until 2026, reaching an all time high of 48.40 GWh/d in May of 2012 and a record low of 0.00 GWh/d in January of 2011.