f Azimuthally Anisotropic Avo And Sand-shale Content

Anomalous horizontal stress conditions within reservoir rock can result in azimuthally anisotropic elastic properties, the effects of which can be observed in 3D seismic data. The amount of stress-induced anisotropy can vary depending on the sedimentary rock type, and on the subsurface stress conditions. In this study, we model azimuthal AVO (AzAVO) and compare it to observed AzAVO in seismic data from the Stybarrow Field, North-West Shelf, Australia. This forward modelling approach allows us to better understand the spatial variation in observed anisotropy over the extent of the survey area. Finally, we investigate the relationship between azimuthal anisotropy (AA) and sand-shale content, and use the relationship to explain variations in AA observed in the seismic data.