Recognition and analysis of seismic facies in the rift successions of the Campos and Santos basins

Abstract

With deep-water reservoirs, the pre-salt scenario in Campos and Santos basins setting heterogeneous and complex deposits, and thus brings new challenges for seismic interpretation. This study aims at the seismic characterization of the rift section (Upper Hauterivian to Barremian, immediately below the pre-salt reservoirs) in the Campos and Santos basins, with the use of 2D seismic data and two well logs. We analyzed the seismic textures, and the integration of lithologic data defined the corresponding to three seismic facies: Seismic facies 1 (fault-border deposits) displays similar behavior in both basins, with occurrence restricted to the fault borders in a wide and well-defined area; Seismic facies 2 (fine-grained deposits) is widespread in the Campos and Santos basins and grades laterally to seismic facies 3; Seismic facies 3 (grainstone and rudstone deposits) has restricted and erratic occurrence in both areas of the high flexural margin, as well as in the deep areas near the depocenter of the analyzed half-grabens.