Agradecimentos: The authors would like to thank the Shell research team for all the support, comments and suggestions to improve the manuscript, the Geophysics Laboratory of the Institute of Geosciences, UNICAMP, for providing the necessary computer resources, and GeoSoftware for providing academic software licenses. RC thanks CNPq for his scholarship (process number 140342/2019-2). EL thanks CNPq for his productivity grant (process number 311491/2019-7). This research was carried out in association with the ongoing R&D project registered as ANP nº CW266675, "Integrated multi-scale analysis of pre-salt carbonate rocks for the characterization and prediction of reservoir properties" (Unicamp/Shell Brasil/ANP), sponsored by Shell Brasil under the ANP R&D levy as "Compromisso de Investimentos com Pesquisa e Desenvolvimento" Ver menos

Abstract: Brazilian pre-salt carbonates encompass more than 70% of the total oil and gas produced in the country nowadays and yet, present several challenges such as heterogeneous composition in mineralogy with the presence of Mg-clays, a complex pore network and diagenetic processes, e.g., dolomitization, silicification and cementation. Rock physics provides a powerful route to understand the elastic behavior of rocks by connecting geology and geophysics. It is known that pore type determination is crucial to understand this behavior. In this paper, we propose a workflow that integrates several methods to obtain depth-variant distribution of pore types and their respective volumes for seven wells in the carbonate-bearing Barra Velha Formation interval. We compared the modeling results with thin sections, performed sensitivity analysis with several parameters (e.g., mineral content, saturation, different aspect ratios) to verify the impact of each one and, analyzed results with hydraulic flow units to search for favorable porosity-permeability scenarios and their relationship with the different pore types. Results suggest that the key parameters impacting the elastic behavior are mineralogy and pore types. Also, compliant pore type may act as connectors between pores with bigger storage capacity, such as reference and stiff pore types. The proposed workflow contributes to understand these complex carbonates, by providing a feasible path to obtain three pore type distributions for each depth point. Calibration with fluid data and especially mineralogy, is essential for the predictions to be as trustworthy as possible and should be applied for each well with available information Ver menos