A methodology for predicting the oil and gas content of local structures using probable statistical methods on the territory of the Izhemsk stage is presented. The main oil and gas prospects in this area are associated with buried structures confined to the zone of Domanik barrier reefs. The goal of the work was to develop a comprehensive probabilistic model for assessing geological risks and ranking prepared structures according to the prospects of their introduction into deep drilling. The work analyzed the morphological parameters of the structures on the roof of the Domanik horizon: amplitudes, areas, absolute elevations of the arches, dimensions of the axes of the structures, as well as the thickness of the Domanik horizon and the distance of the structures from the deep-sea slope. To build probabilistic models, the initial data was divided into two classes: oil-saturated and empty structures. The information content of the selected indicators was assessed using Student's t-test. A statistical difference in the average values of the following parameters was established: amplitude, the size of the long axis of the structures, the thickness of the Domanik deposits and the distance of the structure's arch from the deep-sea slope. Also the least informative parameter - the absolute arch elevation was identified and excluded from further analysis. For a detailed analysis of the parameter values distribution, categorized histograms were constructed according to the classes of oil-saturated and empty structures. At the first stage, conditional interval probabilities were calculated for each parameter and individual probabilistic models of oil and gas content were built. At the second stage, all indicators were combined into a complex model. To assess the quality of the model, a categorized histogram of cosplay probabilities by structure class was constructed, and the obtained probabilities were compared with the results of discriminant analysis. It was established that the model successfully separated empty and oil-saturated structures according to the boundary value of the complex probability of 0.5 units. As a result of applying the constructed model, it was calculated that within the area under consideration, the most promising in terms of oil and gas content was the Pilegorskaya structure.
