New Oil and Gas Plays in the Cis-Urals

Abstract

––The search for oil and gas in folded zones and in the foredeep of the cis-Uralian region for many decades was reduced to testing of easy-to-find closures and reefs located at shallow depths. Many important discoveries were made as a result, but the overall performance of the work remained relatively low. On the one hand, this was due to the poor subsurface imaging of the data for reliable preparation of structures in regions of complex structure. On the other hand, the peculiarities of the development of oil and gas systems in these regions were ignored during the assessment of prospecting sites. In comparison with traditional production hubs centers in the platform regions of the Volga–Ural and Timan–Pechora basins, this distinguishing feature was caused by a thicker sedimentary cover, the variability of its composition and structure, and multiple phases of structural development. Many failures were due to the formation of traps after the passage of the primary migration flow of oil and gas, low capacity of reservoirs, and their fracturing by faults. As shown by interpretation of new geodata using modern knowledge about the oil and gas potential of regions of similar structure, the cis-Uralian region contains poorly studied oil and gas accumulation zones that can contain large deposits. These include blind thrust regions, subsalt traps in development zones of dislocated diapirs, and also stratigraphic and combined traps associated with unconformities and facies changes. The utmost attention is paid to new prospecting objects in the Timan–Pechora basin in which the thickness of the Paleozoic cover has increased. The preparation of new promising objects in these zones has become possible due to new knowledge and better geophysical data.