Distribution of thermodynamic parameters in the Dnieper-Donetsk basin. Relationship with structure and oil and gas content.

• Datum: 2025
• Hauptverfasser: Usenko, Olga, Usenko, Andrii
• Format: Artikel
• Sprache: Ukrainian
• Veröffentlicht: S. Subbotin Institute of Geophysics of the NAS of Ukraine 2025
• Schlagworte: Dnieper Donetsk basin; heat flow; gradient; modern hydrothermal activity; fault zones; hydrocarbon deposits
• Online Zugang: https://journals.uran.ua/geofizicheskiy/article/view/336348
• Назва журналу: Geofizicheskiy Zhurnal

Calculations of geothermal parameters of the Dnieper-Donetsk basin have been carried out. In all fields in part of wells the geothermal gradient is stable and is 20—21 °C/km, and in some it changes. It is negative to the west of the Chernihiv segment, where there are no fields. In its eastern part and the and western part of the Lokhvytsia segment, both positive and negative changes have been observed. In the eastern part of the Lokhvytsia segment and in the near-border parts of the Izyum block, they are exclusively positive. Heat flux within the depression varies from 36 to 56 mW/m2, but over most of the territory it is 39—46 mW/m2. The most common values are 40—42 mW/m2. At the border of the Chernihiv and Lokhvytsia segments, in the southern near-border part and between the Lokhvytsia and Verkhovtsiv-Lgov fault zones (FZ), HF is increased to 45—48 mW/m2. The central part of the Izyum segment is characterized by low HF values (38—40 mW/m2). A major increase happens to the east of Western Azov Region towards Donbas. The spatial distribution of heat flux and temperatures at a depth of 3000 m correlates with the location of the foundation FZ. To the west of the Lokhvytsia FZ, HF changes in areas where the north-eastern stretch zone intersects with the meridional zones. In the triangle between the Lokhvytsia to Verkhovtsiv-Lgov FZs, the influence of the latitudinal FZs (Kyiv—Hadyach and Andrushivka) is also evident. In the central part of the Izyum segment, the distribution of HF corresponds with the location of the latitudinal Starobilsk-Zhmerynka and longitudinal Axial FZs. It is suggested that the increase in the gradient is a parameter of the thermal field that reflects modern tectonic and geological events: the recovery of permeable zones in the sedimentary strata which are related to the faults in the foundation and sedimentary layers, and temperature increase because of the injection of thermal hydrocarbonate-sodium deep waters. The depth of the gradient change is close to the depth of the strata containing hydrocarbon deposits. In the Lokhvytsia segment, gradient changes in the Lower Carboniferous layers, which contain hydrocarbon deposits. In Izyum, the wells do not reach the Lower Carboniferous sediments, and the hydrodynamic regime is caused by the spread of impermeable salt diapirs.