Ivanishin V. Stratigraphical and lithology-geochemical criteria of the oil and gas presence in deep deposits of the Dnieper-Donetsk basin.

Deposits oа the Devonian and Lower Carboniferous were studied. The degree of breaking up of relief of different surfaces and wide development of inversion processes have been established and big triangular (wedge-shaped) structures have been recognized (first) and first the Belskije (Limanskije) deposits have been established in the northern near-slope zone as well as the Tournaisian deposits of big thickness in near axis zone with considerable content of carbonates. The notion about significant role of carbonate rock masses in generation oа hydrocarbons and in formation of their deposits has been advanced and substantiated. First, alternation of zones with worsed and improved reservoir properties (compacted and discompacted zones or zones of compression and stretching) have been established that there is irregularity of katagenetic changes of rocks on area and in section. On the base of the data of complex geochemical researches, a flowing of hydrocarbons fromdepths of more than 6400m has beenestablished, which considerably widens the sphere of prospecting and confirms possibility of the formation of deposits of oil and gas in any depth. Ten main criteria of the oil and gas presence of deep-seated deposits of the Dnieper-Donets Depression have been determinated.