Natural Gas Stocks Injection in Bulgaria remained unchanged at 0 GWh/d on Monday March 23. Natural Gas Stocks Injection in Bulgaria averaged 9.67 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.