Geological Velocity Approach in Order to Obtain a Detailed Velocity Model for the Evaporitic Section – Santos Basin

Abstract

Several exploration areas in Santos Basin, Brazil, focusing the Pre-Salt Section lack a refined velocity model for migration purposes. There are many different techniques to build better velocity models trying to fit as good as it is possible the needed geology for those models. These alternatives are to bring information from old processing efforts, include interpreted horizons, well information, etc. In order to build an optimum velocity model for the migration process, in that case recommended to be the RTM (Reverse Time Migration) at least the recommended approach would be to use more than salt flooding, constant velocity or tomography. In our suggested technique, real geological information is needed in order to build this model. In this work we present a way to build this velocity model using a legacy amplitude data to better find the portions of the data (using 3D analysis) to locate the places where we must have the velocity anomaly to allow for the best image construction. The obtained results will allow us to migrate once again the data as well as to generate input data to perform uncertainty analysis regarding volumetric calculations, geomechanical studies, etc.