The article considers the classification attributes of non-anticlinal traps on the basis of analytical research and critical analysis of literary sources. A certain excess of classification definitions and characteristics of traps, used by researchers both to describe universal schemes and for specific oil and gas basins, and their frequent discrepancies reasonably lead ultimately to an enlargement of types and subtypes of traps, combining them into three main classes of accumulations: continuous and quasi-continuous (unconventional) and discontinuous (conventional). It is noted that in combination with geophysical, seismostratigraphic, paleogeographic, paleotectonic, hydrogeological and other methods of studying the genesis and morphology of traps, and their search, geochemical methods of forecasting and searching for hydrocarbon accumulations at all stages of prospecting and exploration are now widely introduced. The practical possibilities of geochemical methods for evaluating the effective productivity of thin traps of carbonaceous formations are shown on the example of the Bazhenov and Domanik deposits of Russia, as well as the shale plays of the Bakken, Eagle and others in the United States. Keywords: non-anticlinal traps; thin traps; reservoirs; oil and gas; classification of traps; carbonaceous formations; geochemical studies.