Martin Tygel Unicamp - Brazil), Rui Pena Reis (Univ. Coimbra - Portugal), Bjorn A. Rasmussen (Simula - Norway) Martin Tygel Unicamp - Brazil), Rui Pena Reis (Univ. Coimbra - Portugal), Bjorn A. Rasmussen (Simula - Norway) Seismic Imaging of Salt : Processing, Interpretation & Restoration BN21

Agenda Introduction Processing Interpretation Restoration Conclusions

Introduction Both pre-salt and subsalt examples are described in north and south atlantic realms, e.g. Brasil, Norway, equatorial margin, etc. Due to complex geology and excedingly high cost of acquisition and production, seismic imaging studies are in high demand. Meaningful studies require understanding of basin geologies worldwide, in particular those in onshore areas with high quality outcropping conditions Significant discoveries of oil and gas in different basins worlwide, are related to salt occurences and geometries

Processing The Group of Applied Geophysics at Unicamp has made significant advances in seismic data processing in complex geoologies, in particular in salt environments. The main achievement of that Group is the Common- Reflection-Surface (CRS) method, with which clear images and attributes can be extracted from the data The CRS method is able to produce high-resolution time- migrated volumes, amenable to good interpretation. Moreover, CRS time images and attributes provides reliable depth-velocity models for further depth imaging.

Interpretation The images provided by the CRS method at Unicamp will be interpreted by the Geologists at the University of Coimbra. As best practice in the oil companies, the interpretation will be carried out in close connection with the processing in Unicamp, so that the best results can be achieved. The processing & interpretation will be calibrated with well-understood outcropping analogues with significant data provided by the Coimbra Group.

Restoration Interpreted seismic volumes will be handed out to Simula for basin reconstruction studies. The restoration results will be discussed with the processing (Unicamp) and interpretation (Coimbra) groups in asynergetic way, so that the results achieve a most solid scientific base. Numerical framework provided by Simula can describe highly complex deformations and property distributions and reflect the interference of a range of geological processes on the geological timeline.

Examples

Processing/Interpretation: Lusitanian Basin

Processing/Interpretation: Lusitaninan Basin

Processing/Interpretation: Antarctis data

Interpretation/Outcropping

Lusitanian Basin – slope reservoir deposit

Restoration

Present Past

Conclusion Our proposal envisages to produce meaningful seismic geological images of salt environments that relate to Brazil and Norway. The images will be backed by geological interpretation and basin restoration information. The delivered images, together with their interpretation and basin restoration knowledge, are expected to be of great use for oil & gas exploration and production of the two countries.

Thanks for the attention !!