Análise e estimativa de permeabilidade por ressonância magnética nuclear em coquinas da Formação Morro do Chaves, Bacia de Sergipe-Alagoas

Abstract

This work studies the satisfactory of NMR estimated permeability models in coquinas, carbonate rocks formed by the accumulation of shells, common in the Pre-salt section of Campos and Santos basin. In addition, it analyzes the behavior of coefficients of the equations in this type of rock, since these were calibrated for siliciclastic rocks (sandstones). The adjustment of coefficients was made by the Multiple Linear Regression (MLR) method, determined in 45 samples of coquinas from Morro do Chaves Formation, Sergipe-Alagoas Basin, dividing them into two groups: high and low permeability. Finally, the obtained results were applied on two NMR logs from Itapema Formation, formed by coquinas from Pre-salt interval of Santos basin. The observed experimental results show that the coquinas present a behavior more similar with sandstones than with typical carbonate rocks (dolomite, limestone).