Sedimentation-capacity model of the subsalt deposits of the Southern Urals and adjoining territories

Abstract

The junction zone of the Caspian syneclise, the Russian Plate and the Pre-Ural trough is characterized by a complex structure. It has been studied in some detail during large-scale geological, geophysical, and drilling operations in the search for mineral deposits. Subsalt deposits are associated with the main prospects for the growth of hydrocarbon reserves in this region. This makes it important to rethink the available data and conduct scientific analysis to identify patterns of formation of sedimentary complexes and an integrated assessment of their possible hydrocarbon productivity by means of sedimentation modeling. The structure and history of the formation of five large sedimentary complexes: the Ordovician-Lower Devonian, the Central Middle Devonian, the Frasnian-Tournaisian, the Visean-Upper Carboniferous, and the Permian are considered in detail. For each complex, a structural-formational position and sedimentation conditions are determined, which should determine the hydrocarbon productivity of local objects. The revealed relationship between the conditions of carbonate sediments accumulation and their potential reservoir properties served as the basis for forecasting the productivity of regional natural reservoirs. The paper presents a generalized model of the formation of subsalt strata and the forecast of the spatial distribution of different facies deposits, which play the role of accumulating and preserving strata. The results obtained are applicable in the practice of oil and gas exploration in the region

Keywords

• Southern Pre-Urals
• subsalt deposits
• natural reservoir
• sedimentation modeling
• Paleozoic
• carbonate rocks
• shallow-marine sediment accumulation
• hydrocarbon productivity
• sedimentary complexes