The formation of the temperature regime of the Dnieper-Donets depression is determined by the magnitude of the deep heat flux, the structural and tectonic features of the region, the lithology of the sedimentary complex, the occurrence of a thick complex of chemogenic and volcanic rocks in the region, as well as hydrogeological conditions. Based on the analysis of factual geothermal material on wells, obtained during geophysical studies, measurements of temperatures and geothermal gradients, measurements of temperatures during testing of productive horizons, as well as from literary sources, the interpolation of factual geothermal material is carried out. The geothermal parameters characterizing the temperature state of rocks and fluids of different tectonic zones of the Eastern oil- and gas-bearing region have been determined. Schemes of temperature distribution at depths of 2000, 8000 m, average geothermal gradient, depths of isotherms 150 °C, 180 °C are given and regularities of distribution of geothermal parameters are analyzed. The lateral zoning of the geothermal parameters distribution of the region is established, the zones of their maximum, middle and low values are distinguished. Taking into account the peculiarities of the tectonic structure of the Dnieper-Donets graben, as the sedimentary complex is submerged, a gradual replacement of oil by oil and gas fields and then by the gas ones occurs from the northwest to the southeast. Geothermal parameters characterize the geothermal activity of the subsurface and allow to determine its zonation, as well as to predict the phase state of hydrocarbon systems at great depths.
Origin of oil and gas-bearing volcanic rocks recovered by deep drilling in the Niigata oil and gas fields, northeast Japan-with special reference to Sr and Nd isotopic research
