DIGITAL VISCOELASTIC SEISMIC MODELS AND DATA SETS OF CENTRAL SAUDI ARABIA IN THE PRESENCE OF NEAR-SURFACE KARST FEATURES

摘要

Central Saudi Arabian fields are generally known for their high-quality light oil that derives from structural and stratigraphic traps. Despite their unique geological settings, there are no existing digital geological models or synthetic seismic data that are publicly available for testing hypotheses and algorithms. We attempt to fill this gap by compiling 2D viscoelastic models of one of these fields and generate corresponding multi-component synthetic seismic data sets. We selected the Usaylah field because its oil production comes interestingly from a stratigraphic trap in the Permian siliciclastic Unayzah reservoir. Furthermore, to simulate realistic central Arabian near-surface conditions, we generate two models: one with and another without karst features in the top Aruma limestone.The P-wave velocities and densities of the entire stratigraphic column from basement to Aruma limestone were compiled from public sources. We then calculate S-wave velocities from P-wave velocities using empirical V-S -V-P relations that we established and generalized from few published well logs. P-wave and S-wave quality factors were also calculated from the corresponding P-wave and S-wave velocities using an empirical square-root formula. A total of four synthetic 2D seismic data sets comprising the horizontal and vertical components excluding and including karst features were generated using a finite-difference algorithm. We share the models and seismic data sets publicly hoping that this will motivate interested researchers to test their research ideas.