Geology and recovery fator of the brazilian reservoirs

Abstract

The Brazilian sedimentary basins show a dominance of groups of specific reservoir rocks. These groups of reservoirs are the result of specific depositional environments and present distinctive characteristics in geometry and depositional processes. These characteristics control the quality and degree of continuity of the reservoir rocks, and together with the quality of the fluids produced and the production mechanisms are the main elements responsible for the recovery factors (RF) of the Brazilian sedimentary basins. The reservoirs with higher recovery factors are those related to aeoJian, deltaic and deep marine (turbidites) environments, while lower recovery factors are related to alluvial and fluvial origins. This paper shows that for the Brazilian reservoirs the quality and geometry of the reservoir are more important than the production mechanism and/or the secondary recovery process, and the later is more important than changes (of small significánce) of the fluid properties.