US. Energy Information Administration - EIATechnically Recoverable ShaleOil and Shale Gas Resources:Other Eastern EuropeSeptember 2015Independent Statistics & Analysiseia.govU.S. Department of EnergyWashington, DC 20585By country, the estimates areUkraine (128 Tcf and 1.2 billion barrels); Romania (51 Tcf and 0.3 billion barrels); and Bulgaria(17 Tcf and 0.2 billion barrels). 500 /3 200 .