This paper discusses the seismic-based stochastic approach to geological risk quantiﬁcation while localization of geological objects and estimating resources of hydrocarbons. That technique considers a complex of input uncertainty factors: mapping errors, uncertainty of thickness and contact mark prediction, ambiguity of porosity, saturation, density, etc. forecasting. Important part of this procedure is quantitative assessment of input data reliability. Next we simulate listed uncertainties in order to evaluate their inﬂuence on the following results: uncertainty of geological object localization and range of estimated resource value. We use stochastic technique in the risk factors modeling process, particularly error ﬁeld simulation and Monte-Carlo modeling.