Reservatório carbonático de idade albiano: integração rocha-perfil

Abstract

Carbonate rocks are the main reservoirs of hydrocarbons, retaining more than half of the world’s oil. They are susceptible to depositional and diagenetic conditions. These exhibit complex and commonly poorly understood petrophysical characteristics. In this context, it is important to characterize the main depositional carbonate facies, to identify the active diagenetic processes and to classify the different types of pores and connectivity between them, in order to assist in the control and management of these important oil reservoirs. In this work, it was possible to characterize the different permo-porous facies in the Albian carbonates, from oil and gas well of the Campos Basin. Sedimentologic and diagenetic studies, with well log data and statistical methods, were carried out to verify their similarities. The applied methodology allowed the recognition up to three electrofacies with different permo-porous characteristics, through the obtaining of electrofacies associated to the petrographic and petrophysical studies. The electrofacies of the best reservoir quality corresponds to the lithology composed of bioclasts, corresponding to bioclastic rudstone (RB) microfacies, which keeps a direct relationship with the petrophysical properties and the electrofacies. The correlation of the petrophysical properties with the depositional microfacies proved to be quite complex, due to the diagenetic processes.