This article gives a brief overview on the possible forecast of oil and gas content on the basis of the studies of DOS (dispersed organic substance) rocks and its catagenetic alteration. On an example of southern part of Buzulukskaya hollow the connection of paleozoic rocks catagenezic with the phase content of hydrocarbons deposits is traced. The original scheme of catagenetic location of the bowels for this territory has been devised on the basis of the usage of the method of calculation of total impulses of heat. It is suggested to use the data of definitions of catagenesis on several stratigraphic levels in the group of chinks for the revealing of mathematic connection of the degree of its development with modern depth of the rocks deposition.