Grzegorz Machowski

3D Static Models as a Tool to Indicate Prospective Geological Structures for EGS in Sedimentary Rocks of Central Poland

The paper illustrates the results of 3D static modeling in sedimentary cover of the Polish lowlands and their suitability for characterizing Enhanced Geothermal System. The resultant basic structural framework of the EGS systems model covers an area of ca. 36000 km2. It is composed of 13 structural horizons, starting from the base of the Carboniferous strata up to the top of the Cretaceous succession, and contains 12 stratigraphic zones being equivalents of stratigraphic epochs. The results of structural and parametric modeling were finally presented as maps of average parameters and effective thicknesses, superimposed on maps of temperatures related to the tops of the mapped zones. Superposition of depth, thermal and reservoir criteria allow to indicate spatial extent of hypothetically favorable conditions for EGS/HDR development. The results of static modeling indicate that relatively favourable conditions for EGS systems development can be expected locally of Upper Rotliegend and Carboniferous reservoir. The most important problem referring to practically the whole area of interest is lack of good quality data.

ZTE MRI in high magnetic field as a time effective 3D imaging technique for monitoring water ingress in porous rocks at sub-millimetre resolution

Zero echo time magnetic resonance imaging (ZTE MRI) at 9.4T was used to assess the local distribution of water in dolomite rocks under different saturation conditions. The results were compared with the industry standard Single Point Imaging (SPI) at 0.6T. 3D maps of the local amount of water saturating heterogeneous rock were obtained from the imaging data, and correlated with the corresponding structural images from high resolution micro-CT (μCT). The method can be applicable in the investigation of spatial kinetics of water saturation processes in porous, heterogeneous rocks where imaging methods based on spin echo, such as RARE, have failed due to short T2, while SPI is often impractical due to its long acquisition time.