Resolution enhancement with relative amplitude preservation for unconventional targets

Abstract

Our primary objective was to evaluate a method that enhances the resolution of 3D seismic data that does not disturb the relative amplitude preservation. The formations that are the subject of the analysis are Lower Silurian: the Jantar Formation and the Ordovician Sasino Formation (the onshore part of the Baltic Basin, northern Poland). Both formations are seismically thin layers and have been recent targets for unconventional exploration. Resolution enhancement designed to help the structural interpretation may enable precise structural interpretation of thinly layered intervals. The method that we applied is poststack spectral blueing. To verify the effectiveness of the spectral blueing procedure, we designed an algorithm that compares the amplitude values along evenly distributed seismic traces. The algorithm addresses the preservation of the relative amplitude ratio. We did not want to disturb the amplitude values by the enhancement algorithm and introduce information that would be false for seismic inversion analysis. Hence, it was crucial for us to obtain the enhanced seismic volume suitable for structural interpretation that holds relative amplitude relation criterion. The algorithm helped obtain the optimal enhanced seismic volume that is preferable for the structural interpretation of seismic data and possibly could be used successfully for a seismic inversion process. With the optimal enhanced seismic volume, we were able to conduct a more accurate structural interpretation — an entirely new seismic horizon that indicates that the top of one of the formations under analysis was clearly visible and thus possible for interpretation. We applied the acoustic inversion to the original and the enhanced seismic data — the latter enabled the determination of two additional anomalous zones that had not been previously possible to distinguish within the seismic volume.