Geophysical And Log Characterization Of Roncador Field, Campos Basin, Brazil

Roncador oil field is a giant accumulation located in the northern area of Campos Basin, Brazil, in a bathymetric<br>contour varying from 1,500 to 1,900m. The reservoirs are maastrichtian turbidites and based upon their<br>distribution, the field may be divided in three areas (SE, SW na N). In the southeastern part five main zones are<br>identified; the sandstones are interbedded with shales and only the upper part may be associated to<br>conventonal sesmic amplitude anomaly. In the southwestern area of the field, the turbidites are amalgamated,<br>indicating incomplete depositional cycles except the highest part of the sequence where interbedding shales are<br>present. The northern area of Roncador acted as a bypassing zone during the lower sandstone deposition time<br>in the southern area of the field and only the the upper reservoirs were deposited. The sandstones are<br>characterized by textural and compositional immaturity. The rate of subsidence associated with halokinesis and<br>the preservation of sediments from erosion control the reservoir distribution differences along the field.