Givetian Sedimentation in the Southern Part of Buzuluk Depression

Study area is the southern plunge of Buzuluk Depression, which belongs to Middle Volga petroleum region (south of the Volga-Urals petroleum basin). Main hydrocarbon productivity is related to terrigenous and carbonate deposits of Eifelian and Givetian. They are represented by Klintsy, Mosolovo, Vorobyevka and Ardatov horizons within study area. These deposits contain oil and condensate pools in the Zaykinsko-Zorinskoe, Sakharovskoe, Garshinskoe, Rostashinskoe, Konnovskoe and other fields. Givetian productive sandstones and overlying clayey seals have various reservoir properties and complicated distribution of the reservoirs in the section. It is first caused by depositional environments. Complex analysis of results of macroscopic and microscopic core examination, well logs and seismic data interpretation allowed developing sedimentary models of Middle Devonian deposits. It became a reason for prediction of petroleum reservoirs distribution within the section. Givetian sandstone reservoirs within areas with increased thickness of overlying seals are the most perspective from the viewpoint of hydrocarbon productivity. Consideration of these sedimentological and tectonic factors may help to discover new oil and gas fields within the southern plunge of Buzuluk Depression. Application of received conclusions in oil and gas exploration may raise the level of its effectiveness.