Geological exploration risk is a possibility that the exploration operations won’t confirm gas-bearing capacity of the research objects. It is determined by the level of uncertainty, taken into consideration when obtaining data on the state of the hydrocarbon feedstock base and making decision on its expansion. Risk is an inevitable part of the resource estimation, when the final result is unknown, but there is a degree of probability of gaining certain results. There is no exact system of probability measures that influence to the maximum the transfer of resources to reserves and the assessment of geological risks. The main goal of the geological and economic survey of the feedstock base is the minimization of geological risks influence on the final results of the site economic attractiveness estimation.