Transformation of TUNB3D-NI into a 3D Volume Model: Insights from the TUNB Velo 2.0 project in Lower Saxony

For Lower Saxony, the model TUNB3D-NI consists of 13 lithostratigraphic units from Zechstein to Tertiary in the North German Basin. Furthermore, it includes salt domes and major fault systems. In the project TUNB Velo 2.0, the 3D structural model will be transformed in a 3D volume model and parameterised with reasonable seismic velocities. The resulting model enables to convert information on a regional scale from time to depth domain and vice versa.

Currently, we are working in a pilot region in the eastern part of Lower Saxony. Data from previous regional velocity studies (Jaritz, 1991), borehole measurements and seismic velocity analysis serve as the input for velocity interpolation and quality control. In Aspen SKUA, the regional velocity model is build with two different modelling approaches: A voxet is created with regions defined by the lithostratigraphic units. Within the regions, the velocities are assigned based on a depth dependent formula with the “Apply Script” command. For the second approach, the velocities in depth are generated with EPOS` SeisEarth module. After import in Aspen SKUA, we used the “Structure & Stratigraphy” workflow to generate the 3D volume model. It is parameterised with the “Reservoir Properties” workflow afterwards.

On the poster, we will provide insights in the modelling process, compare both methods and show the resulting velocity model.

References:

Jaritz W., Best G., Hildebrand G., Jürgens U. (1991) Regionale Analyse der seismischen Geschwindigkeiten in Nordwestdeutschland. Geol Jahrb 45:23–57