Natural Gas Stocks Injection in Bulgaria increased to 44.26 GWh/d on Sunday September 27 from 44.15 in the previous day. Natural Gas Stocks Injection in Bulgaria averaged 10.13 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.