The one-step seismic inversion approach inverts directly from seismic amplitude data to reservoir properties, which makes the propagation of the uncertainties more accurate than the standard two-step approach. Direct Probabilistic Inversion (DPI) is a one-step approach, where information from seismic amplitude versus offset (AVO) data are integrated with the geological knowledge, such as stratigraphic ordering, expected lithologies and fluids within each stratigraphic layer, fluid gravitational ordering, thickness distribution of facies, and transition probability between one facies and the next. The injection of this valuable geologic information, previously ignored in standard deterministic AVO inversions, helps mitigate ambiguities inherent in the seismic method. In this study, DPI is applied to different seismic datasets across different Australian basins to show the efficiency of the method for predicting seismic facies and reservoir properties even for thin reservoir and coal layers despite being below tuning thickness.

Open-Access Online Publication: May 29, 2023