Use of geophysical logs to map aquifers electrofacies

Abstract

Map of geophysical parameters in different depth and their corresponding geological interpretations are analyzed based on an automatic geostatistical method to aquifers electrofacies identification using geophysical well logging curves of electrical resistivity, gamma ray and sonic transit time. The methodology for the spatial analysis of the variability of petrophysical characteristics considering their borehole geophysical responses, useful in oil industry, is extended here in water research. For that, they were used 65 geophysical logs scattered throughout the metropolitan region of São Paulo (Brazil) carried on between 1997 and 2012. In addition, the combined use of these three parameters has led to a better understanding of the subsurface rocks in the complex stratigraphy of Paleogene São Paulo Basin, Brazil, in order to future projects of planning groundwater wells.