19^th International CODATA Conference
Category: Data Visualization

3D visualization and interpretation of a geothermal aquifer, based on pre-existing drill hole and 2D seismic data

Inga Moeck (inga.moeck@gp.tu-berlin.de), TU Berlin, Institut für Angewandte Geowissenschaften, Germany
Dr. Heinz-Gerd Holl, GeoForschungsZentrum Potsdam, Section Geothermics, Germany
PD Dr. Heinz Schandelmeier, Prof. Dr. Wilhelm Dominik, TU Berlin, Institut für Angewandte Geowissenschaften, Germany

At the end of the 1950's intensive exploration geophysics and drilling campaigns were launched on the territory of the former German Democratic Republic in order explore the mineral and hydrocarbon potential of the country. From this huge data base, 15 wells and 5 seismic sections of the Groß Schönebeck area (45 km north of Berlin) were reassessed in order to describe the subsurface geology in the vicinity of the geothermal in-situ laboratory which was installed in the well Groß Schönebeck 3/90. Based on these data a 3D model of the area was calculated with the 3D modelling software EarthVision developed by Dynamic Graphics Inc..

The seismic sections, which had been re-processed for this purpose by GGD Leipzig, were combined to form a coherent 3D data set in order to visualise the spacial distribution of geologic layers and faults. In a next step the 3D layer model was correlated and, where necessary, corrected with the help of the well data. Finally a 3D model of the geometry of the facies body of the ca. 4000 m deep geothermal lab reservoir was calculated to indirectly estimate the porosity distribution. This information is important to determine the reservoir capacity. We integrated the facies model into the 3D model, which may be perspectively viewed from any selected direction, sliced into cross sections or dismantled to visualise the reservoir horizon.

Moreover, the 3D model reveals the extent of salt deposits, which may attain locally a thickness of more than 1000 m. These salt deposits are of pillow- or dome-shape in the zones of highest thickness and are considered to potentially influence the groundwater aquifers because of their high solubility. Our geologic 3D model reveals the salt deposits being in lower depth as was hitherto assumed.

As our example shows, the re-interpretation of pre-existing data with new technologies can reveal new knowledge and understanding. In future this should be taken into account in achieving geoscientific objects, specially in the area of the formerly GDR, where a huge amount of geodata already exists.