Analysis of the Mineralogical Composition of Shales - Case Study Araripe Basin

The Araripe Basin is the largest basin in the northeastern interior, located in the border region of the states of Ceara, Pernambuco and Piaui, and has enormous influence on the climate and the local economy. Well known for its paleontological occurrences, this basin has also become the target of research aimed at knowing the potential of its rocks as generators or as reservoirs of hydrocarbons. For the accomplishment of this work 4 samples of black shales that appear in gypsum mines exist in the Ipubi Member of the Santana Formation were used, in order to characterize their petrophysical properties, which are still little known. These properties are determined for subsamples through the analysis of X-ray microtomography images, including mineral and organic composition, apparent and actual grain density. In general, the analyzes indicated a high content of organic matter, evidencing the hydrocarbon potential of these shales. Thus, computational petrophysics shows itself as an important characterization tool for the study of the behavior of the properties of a rock.