Petrophysical Characterization of Heterogeneous Carbonate Reservoirs for Geological Modeling – The Case of Buzios Field, Brazil

The petrophysical model, which includes porosity, permeability, and fluid saturation, is essential for developing a reservoir’s geocellular model. This paper highlights the multidisciplinary approach used in the petrophysical model of the Búzios Field, located in Brazil’s Santos Basin and discovered in 2010. The reservoir consists of carbonate rocks from the Barra Velha and Itapema formations. The availability of high-quality seismic data and around 100 drilled wells has facilitated the creation of accurate petrophysical models.

The porosity model incorporates both matrix and extra-matrix porosity, with matrix porosity derived from density profiles and mineralogical modeling, while extra-matrix porosity comes from image log segmentation. This led to the construction of 3D models that account for these porosities and utilize geostatistical techniques. The permeability modeling integrates laboratory data and formation tests. Matrix permeability is determined using the FZI methodology, while horizontal and vertical permeabilities are derived from correlations and flow capacity measurements.

The water saturation model is based on capillary pressure test data. and The resulting 3D model effectively captures the field’s heterogeneity, enhancing volumetric calculations and productivity estimates through collaborative efforts across disciplines.