Caracterização multiescalar petrofísica e mineralógica de folhelhos da bacia do Araripe.

Abstract

Unconventional reservoirs have been widely studied due to the increase in world energy demand and are complex reservoirs. One of the great challenges of the oil industry is to make the production of non-conventional reservoirs economical and safe. The Araripe Basin is one of the Brazilian basins that present this type of reservoir, and few studies has been developed in that basin to date. In this research, 4 samples of black shales were studied in order to evaluate the porosity, total density, grain density, pore connectivity and mineral composition. The methods used in the research are X-ray microtomography (μCT) and X-ray nanotomography (nCT), non-destructive and advanced methods for petrophysical characterization, as well as their integration with X-ray diffraction (XRD) and thin-seition petrography for mineralogical identification. The results of the analyses indicate that the samples have a relatively high porosity, and the connectivity were considered good only for the micropores. The results show that the characterization of the minerals, by the different methods, converges to the main minerals (high contents) and diverges for those with small levels (accessory minerals). The shales analyzed have a high content of organic matter, evidencing their hydrocarbon potential.