The junction zone of such large tectonic structures as the Volga-Ural anteclise, Precaspian depression and Pre-Ural foredeep is characterized by a very complex tectonic structure, history of geological development and formation at different phases of diverse paleogeomorphological settings and related sedimentary petroleum bearing strata. Within the limits of territory of research, corresponding to southern and southeast part of Volga-Ural and north of Pre-Caspian petroleum Province for the last eleven years 73 accumulations have been discovered. Rate productivity of all Paleozoic cover beginning from Middle Devonian (Biysk level) up to Lower Permian has been established. Total number of accumulations in this zone is more than 160 in the Russian part and 14 in the territory of the Republic of Kazakhstan, among which oil accumulations prevail, oil-gas condensate and gas reservoirs are also discovered. The complex Paleozoic paleorelief caused diversity of sedimentation conditions, formation of sedimentary bodies of different composition and genesis: single and barrier reefs, carbonate clinoforms, avandeltaic sand and sandy-siltstone-clay sequenceses, shallow carbonate and sandy bar, representing independent lithological HC traps. On the basis of complex lithologic-stratigraphic and sedimentological analysis of drilling and seismic data, sedimentary models of different zones of paleobasin were developed for Lower Devonian potentially petroleum bearing, Middle Devonian Eifelian, Middle-Upper Devonian Givetian - Lower Frasnian, Upper Devonian - Tournaisian, Upper Visean - Lower Bashkirian and Middle Carboniferous - Lower Permian petroleum bearing strata. Various types of lithological and stratigraphic traps are distinguished, the characteristics of reservoir types and their content in the sections of sedimentary bodies are given. Geological and geophysical standard of well sections for sedimentary structures of different genesis are compiled. Prospective zones containing objects of lithological type are distinguished.

Summary Accumulation of oil (field) in the domanic sediments is an area of layers distribution or groups of layers into the Domanic section in which oil is found in disseminated state and its petrophysical rock properties give opportunities to take commercial oil flows after carrying out reservoir fracturing. In Russia for commercial development and also pilot projects it is necessary to carry out the estimation reserve at once after deposit discovery. That is why for operative oil reserve estimation for unconventional it is possible use only reserves estimation volumetric method. For oil reserve estimation by volumetric method in Domanic is proposed the algorithm