Gravity anomaly of the Fazenda Alvorada Field, Bahia

Abstract

The Fazenda Alvorada oil field, discovered by PETROBRAs in 1984, is located in the northeastem portion of the Recôncavo Basin, Bahia, Brazil, in the upper block of the Pedras Fault. It comprises three individual oil accumulations in small faulted block 01 the Sergi Formation. With the purpose of resolving structural details generally masked by regional gravity anomalies, different techniques for regional-residual separation were analyzed. Bouguer anomaly data were submitted to five different filtering methods. The residual maps obtained were well correlated with the structure of the field area. Polynomial adjustment was used to detail the anomaly and a seventh-degree polynomial surface used to approximate the regional field. The residual map shows the subdivision of the principal anomaly into two smaller anomalies, correlated with the structure of the Fazenda Alvorada oil field.