Common structural features and petroleum potential of Upper Devonian-Tournaisian carbonate and argillaceous-carbonate sequences in near-flank zones of Kamsky-Kinelsky trough system

The authors discuss common structural features and petroleum potential of the Upper Devonian-Tournaisian carbonate clinoform sequences well represented in the near-flank zones of Kamsky-Kinelsky trough system in the Volga-Urals Petroleum Province. Characteristics of reservoir types and special features of their occurrence within clinoform sequences (hydrocarbon stratigraphic traps) are presented. The authors recite the criteria for their identification using drilling and seismic data. Methodology of reference geological and geophysical section development for different depositional zones of the paleobasin is applied; the mentioned zones are: outer, inner near-flank and central zones of Kamsky-Kinelsky paleotroughs, and slopes of South Tatarsky, North Tatarsky, and Bashkirsky paleoarches. Lithofacies characterization of Upper Devonian-Tournaisian deposits of the Aktanysh-Chishminsky paleotrough and South Tatarsky paleoarch are presented. The authors discuss main rock types that compose clinoform bodies of submarine fans (clastic carbonate material) on the outer slopes of paleoarches and in the near-flank zones of paleotroughs. Lithofacies models showing the structure of main depositional zones and evolution of the sedimentation basin in the Middle - Later Frasnian, Famennian, and Tournaisian time are created. Geoseismic criteria for carbonate clinoform bodies identification and mapping are pointed out.Basing on the integrated interpretation of the recent 2D seismic and drilling data, prediction of stratigraphic traps in the Famennian and Tournaisian carbonate clinoforms on the slope of South Tatarsky arch and in the Blagoveschensky depression is conducted