Petroelastic Seismic Inversion for Reservoir Modelling in the Vienna Basin

Koenig, Michael; Angerer, Erika; Rieser, Erwin; Korinek, Rudolf

The Vienna Basin is an extensional Basin between the Eastern Alps and the Western Carpathians with mainly siliciclastic oil and gas reservoirs. One example is the Erdpress structure. Several multi-stacked reservoir units form 3-way-dip closures within the Neogene sediment succession. The geological static reservoir model of Erdpress includes 10 of these units. A petroelastic seismic inversion was conducted on the prestack depth migrated seismic data in order to be able to quantitatively derive essential reservoir parameters like porosity, shale content, and hydrocarbon saturations. A petroelastic model (PEM) is built from well log data that links these reservoir parameters with the elastic rock properties, P-wave velocity, shear-wave velocity and density, which are measured by the seismic. The seismic inversion directly gives the reservoir parameters via the inbuilt PEM. Further, the inversion results are output directly in a reservoir grid so that these can be used in the modeling. In the Erdpress field the petroelastic inversion yielded excellent results, especially for porosity that were checked along the well locations. Known geological trends were also reflected in the inversion results. These were then integrated into the static reservoir model. The previous reservoir model had mainly been based on geostatistical methods and geological concepts. By using the seismic inversion results to populate the properties of the model it is now a much more data driven, deterministic reservoir model which gives much better results in the reservoir simulation. Further, the petroelastic results formed an integral part in the next well planning campaign.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013