The current practice of geological risk evaluation at the play level involves substantial subjectivity and rarely considers the spatial correlations among the identified prospects. A quantitative procedure using multivariate and Bayesian statistical methods is proposed, which treats exploration-risk evaluation as a two-group classification, to provide a more objective and reproducible result. The spatial correlation among the identified prospects is considered because the proposed approach is applied to the entire evaluation area. The exploration-risk evaluation of the Upper Triassic-Lower Jurassic Heiberg Group structural gas play in western Sverdrup Basin, Arctic Canada, illustrates the method.