Abstract

Silicification is a diagenetic process frequently identified in Aptian Pre-Salt carbonates sedimentary successions, characterized by replacing carbonate minerals with silica. This work aims to propose a methodological analysis to integrate borehole image, elemental capture spectrometry and thin section to characterize silicification on the permoporous properties of the Barra Velha Formation (Santos Basin). Based on the behavior of the silica volume observed in the well, the Barra Velha Formation was divided into five intervals (S1 to S5). Then, the geophysical logs were associated with permoporosity data to identify silicification impact on permoporous properties. Given that, it was observed a trend of increasing silicification upwards the Barra Velha succession associated with permoporous properties reduction in the same trend. However, simultaneously increase of silica content and permoporosity properties in the same depth were characterized as local anomalies. These interactions allow the comprehension that the migration and accumulation of silica volumes along the studied area, in the Barra Velha Formation occurred due to hydrothermal Silica-rich fluids that ascended through fractures and faults, favoring calcite dissolution, generating secondary porosity, and totally or partially cementing the pores.