Keynote 1: Facies Probabilities – Seismic Inversion Coming of Age

Summary Methods for the inversion of seismic amplitudes have been available since the 1970s but their track record of delivering useful results has been, at best, mixed. The realisation of the shortcoming of each method, for example,the failure to account for AVO effects or the ignoring of a key source of uncertainty, has been followed by a change of direction and a new inversion framework, until that one too proved to be inadequate. But perhaps the most recent class of inversion applications, to estimate facies probabilities, will prove to be an approach that can deliver a reliable product. There is still much work to be done to improve the performance of these algorithms; analysis of the inversion problem within this framework more clearly demonstrates the difficulty, but this time the effort could result in successful outcomes.