24 selected anticlinal and fault trap prospects in the Cooper Basin, that do not include certain prospects which are small or which contain discovered but as yet undefined fields, have been evaluated by the SADM Petroleum Geology Section using a new statistical method of petroleum resource analysis. The method has already been used to some extent by the Commonwealth Bureau of Mineral Resources for estimating the potential of offshore petroleum prospects in Australia, but that body now wished to test the method on an onshore sedimentary basin. SADM have borrowed the computer program designed to perform the analysis, and have assessed the chosen prospects from the point of view of estimating gas reserve potential in 3 plays, namely, structural closures in the Toolachee, Epsilon and Patchawarra Formations.The results for each play have been risked individually, and then have been critically re-assessed against the results of drilling of 2 of the prospects (Kidman and Narcoonowie) that have recently come to hand. Comparison of the Kidman Permian gas pool sizes with the theoretical results shows that there are considerable problems with this method of prospect evaluation, which appears to be geared to produce an excessively low, pessimistic estimate of undiscovered petroleum resources.