Characterizing Evaporitic Section and Geomechanical Properties Using Seismic Inversion, a Case Study for Santos Basin

Abstract

Knowledge of the evaporitic section above pre-salt reservoirs in Santos Basin is an important aspect to be observed when preforming geomechanical analysis, especially regarding drilling aspects, injection and production rates. Existing geomechanical models do not necessarily represent a realistic geology for this section concerning the salt variety observed when drilling wells. Occasionally, geologic features are indicated when preparing the well forecast only by taking into account the seismic description and uncertainties identified for the well path. Therefore, a more realistic description of rock properties in the evaporitic section can be used to improve the studies on drilling safety and geomechanical models. One way to achieve this is by using model-based seismic inversion and well log derived relations between acoustic impedance and properties used as input to the geomechanical models. Additionally, statistical facies classification, based on Bayes´ Theorem, can be carried on the evaporitic section with the same intent. In this study we present the seismic inversion results along with the workflow used to generate other rock properties for a specific area in Santos Basin proposed by Maul et al. (2016).