Petrographic and Petrophysical Characterization of Sandstones from Rio Bonito Formation, Paraná Basin (Southern Brazil).

Abstract

This study focuses on the laboratory-scale petrophysical characterization of sandstones from the Rio Bonito Formation (Lower Permian), Paraná Basin, carried out from drill core samples from well PN-14-SC.02 obtained by CPRM-Brazilian Geological Service in the 1980s on the eastern edge of the Basin. This study includes integrating experimental data from routine petrophysics, sedimentary petrography, and nuclear magnetic resonance (NMR) obtained from 6 samples arranged in the normal direction of the stratification, present between 40 and 200 m deep. It was possible to conclude that the values of the permeability and porosity properties obtained from the NMR technique correlated in a very satisfactory way, with correlation coefficient R2 = 0.957 and Root Mean Squared Error (RMSE) = 0.208 about the porosity reference results offered by routine petrophysics, with lower values being less than a porosity unit (+/- 1 p.u.), in the range between 8 and 14%. The same was observed for the estimated permeability, R2 = 0.885 and RMSE = 0.152, by the Timur Coates method, with values in the range between 0.096 and 2.42 mD, which were well supported by the spectra information, as well as by petrographic analyses.