Arcabouço estratigráfico de alta resolução do Campo de Rabo Branco, Bacia de Sergipe-Alagoas : uma abordagem sismoestratigráfica

Abstract

Revitalization campaigns for mature onshore fields in Brazil have made the Rabo Branco Field an important focus of study. Located in the onshore portion of the Sergipe SubBasin, southeast of the Carmópolis Field in the Sergipe-Alagoas Basin, the field presents significant potential for new analyses aimed at increasing its recovery factor. This study aims to conduct a high-resolution stratigraphic interpretation of the field based on five wells, integrated with a seismic-stratigraphic approach emphasizing the Muribeca, Riachuelo and Cotinguiba Formations. Four seismic facies were defined, representing distinct depositional environments: undulated and segmented seismic facies, respectively associated with a fluvial environment and deposition surfaces linked to faults, both related to the Muribeca Formation; subparallel seismic facies, indicating platform environments, associated with the Riachuelo and Cotinguiba Formations; and chaotic seismic facies, related to gravitational flow deposits of the Calumbi Formation. We defined low, medium, and high frequency sequences based on the detailed analysis of the composite well logs, allowing the identification of three higher-order systems tracts based on T-R cycles. The results indicate that wells 4-GALP-36-SE, 1-GALP-12- SE, and 1-CAB-02-SE are positioned in a depocenter region, considered more distal, while wells 1- GALP-11-SE and 1-VF-01-SE are located in a more proximal area. It was observed that the Regressive Systems Tract 1 mainly coincides with the reservoir intervals of the field, corroborating previous interpretations not published in the literature, that indicate the petroleum system is mainly associated with the Carmópolis, Ibura, and Oiteirinhos members of the Muribeca Formation, being the source rock from the rift stage.