Types of tectonic dislocations in connection with the formation of salt structures and hydrocarbon traps of the Dnieper-Donets depression

Abstract

The Dnieper-Donets deprеssion is the main oil and gas region of Ukraine, characterized by the spread of saltdome structures — objects of oil and gas exploration. The complex of geological and geophysical data in the basin distinguishes numerous faults and breaks of different depths of occurrence and duration of development. In salt regions, the disturbances are of great importance in the formation of structural forms that are traps for oil and gas and contribute to the conservation of hydrocarbon deposits. The distribution of hydrocarbon deposits is determined by the morphological features of the structures, the binding of certain types of uplifts to individual tectonic zones, the presence of a network of discontinuous disturbances and the prevalence of the area and section. The research is based on the results of a new interpretation of the geological and geophysical material, in particular, seismostratigraphic section of regional profiles, which made it possible to characterize the types of major disjunctive tectonic disturbances adjacent to salt bodies within the central part of the depression. The oil and gas content of the studied salt structures is directly related to the development of marginal deep and nearedge faults, internal fault pairs, the northern and southern pre-axial and axial faults in the near-stock and overstock zones, as well as disjunctives, “bush-like” faults, faults chasm-like mini-grabens. Tectonic disturbances contributed to the migration of hydrocarbon fluids into the upper layers and the formation of tectonically shielded hydrocarbon traps; salt and clay layers served as reliable impermeable seams; lateral faults controlled the spread of salt, forming a sculpture of the stocks.