f Pseudo synthetic seismogram from statistically derived sonic log: a case history

Geological and geophysical review of mature areas with old wells having only a limited set of logs, has often to tackle the problem of a correct time-depth conversion that is necessary for a suitable identification of horizons interpreted on seismic sections. The lack of acoustic logs, in fact, cannot be compensated by using check shots survey data that, particularly in case of stratigraphic interpretation, do not offer a sufficient detail. In these situations it is necessary to develop a methodology allowing the automatic reconstruction of the sonic curve. In the shows example, the reconstruction has been done following a statistical-probabilistic approach differentiating from any deterministic method (Faust,1955) based on a predetermined mathematical formula empirically extrapolated.