Geophysical Methods in the Recognition of Geothermal Resources in Poland-Selected Examples

Seismic and magnetotelluric methods are most frequently used under Polish conditions predominant by low temperature geothermal associated with sedimentary complexes and crystalline rocks. The application of those methods to recognizing of geological structure and differentiation of petrophysical parameters is presented in the work. The examples of hydrogeothermal investigation in sedimentary complexes of Polish Lowlands and crystalline rocks of Sudetes area are used. The results demonstrate that seismic structural interpretation and seismic inversion can effectively support the selection of areas optimal for future geothermal investments inside sedimentary complexes. Simultaneously, such methods can be important for determination of hydrogeothermal parameters of particular aquifer. Results of seismic inversion can be applied to porosity estimations. Within the crystalline rocks non-seismic methods are usually used, mainly different variants of magnetotelluric method. This method allows to recognize resistivity distribution in geological medium. Geothermal reservoirs inside crystalline rocks are usually connected with fractured tectonic zones conducting warm and mineralized water. Such zones appear as low resistivity at the background of predominant, radically high resistivity rocks.