Maps of deep heat flow and geothermal resources in Ukraine http://gpimo.nas.gov.ua/en/node/1176

Abstract

A technique for processing the material used to map the deep heat flow (HF) on the territory of Ukraine and constructing a map of geothermal resources on its basis is considered. We are talking about the deep (corrected) HF, since its error (determined by the differences in values at close points) is noticeably smaller than in the observed one, and only its values can be used to build thermal models of the earth's crust and upper mantle and solve the indicated applied problem. Due to the unique study of Ukraine in this parameter, which has been going on for almost 60 years, there are still significant fragments of the territory where the HF has not been determined. This is due to the lack of boreholes in such areas suitable for temperature measurements in the required depth interval with the required accuracy. Of course, any means of processing the experimental material in the territories adjacent to such white spots cannot completely replace a full-fledged study of HF within them. Nevertheless, the existing methods of geostatistics allow, by processing the available network of results, to ensure the construction of a map of the entire study area. In our case, the kriging technique was applied. The method works best inside a wrapper defined by peripheral data. In areas with a stable «wavelength» of HF anomalies, it is possible to fill in the gaps of the map without any problems. Naturally, with a noticeable smoothing of field variations. Most of the processed fragments of the map belonged to this type. A new edition of the description of the distribution of Ukraine's geoenergy resources is considered. We used a map of the deep heat flow processed by the kriging method and the construction of maps by region with the calculation of thermal conductivity at depths of up to 6 km at their contacts. This allowed to fill in the gaps in the network of experimental data and clarify the position and intensity of parameter anomalies in the southern part of the Carpathians, the north-eastern slope of the shield, in the Donbass and improve the overall assessment of geoenergy resources (up to 1.1 trillion tons of reference fuel). Geothermal energy from the deepest possible extraction interval (5.5—6.0 km) is about 26 times larger than the reserves of all fossil fuels in Ukraine.