Geostatistical Seismic Inversion: One Nugget from the Troia Conference

One of the characteristics that struck me most about Andre when I first met him in 1980 was the constant desire to expose, discuss and, above all, make accessible the emerging ideas of geostatistics. It was easy for Andre's first group of Stanford students to learn and have a great deal of confidence in what they learned. It was clearly a breakthrough in relation to the existing geostatistics teaching and research culture. It was in this context that the Fourth International Geostatistics Conference was organised in 1992 in Troia, and Andre was the main driving force in the organisation of that event. It was an impressive showcase of the brilliant ideas of the newly created Stanford Center for Reservoir Forecasting. The resolution of an inverse problem with the integration of seismic in the high-resolution stochastic subsurface models was one of the most remarkable nuggets presented at that conference. Louis Bortoli, Francois Alabert, Andre Haas and Andre Journel are the authors of the seminal paper on geostatistical inversion. As an interface methodology between two areas of knowledge, it was not easy to get this new type of model accepted by the geophysics community, which at the time was dominated by deterministic models of inversion. This paper presents a summary of this path and the main geostatistical methods for seismic inversion that have been developed since then, and which have today become a set of practical tools for characterising mineral resources in the petroleum and mining industry.