Geostatistical AVA Seismic Inversion for Reservoir Characterisation of the Pozo D-129 Formation: A Case Study in San Jorge Basin, Argentina

A comprehensive seismic reservoir characterisation study was conducted in a gas field in Argentina, utilising geostatistical AVA seismic inversion to generate input for reliable static and dynamic model simulation. The study encompassed a range of disciplines, including petrophysics, rock physics modelling and geostatistical AVA seismic inversion, followed by effective porosity co-simulation. The key advantage of the geostatistical inversion method lies in its ability to integrate all available data, i.e. wells, seismic, and geological knowledge, resulting in outcomes that honour all input and produce reliable results. A notable aspect of this study was the use of 3D prior probabilities models for geostatistical inversion which proved to be crucial for better characterisation of litho-facies across the area, outperforming the 1D approach. The results of the geostatistical inversion, combined with the conceptual depositional model and previous seismic attributes study, showed significant consistency, increasing confidence in the outcomes of the geostatistical inversion. The results of this study will be used to build static models of the field, enabling estimation of the in-place gas volume and its associated uncertainty. These models will also serve as input for dynamic simulations for the future development of this field.