Using 4D Sseismic to Monitor and Characterize Marimba Field, Campos Basin, Offshore Brazil

Understanding saturation and pore-pressure changes is very relevant in mature fields, in this paper we used and compared two pre-stack 4D data, 1984-1999 Streamer-Streamer (S4D1) and 1999-2005 Streamer-OBC (S4D1) to monitor the Marimbá Field reservoirs – offshore Brazil, its oil production started in 1985. Time-lapse seismic data on this field have been successfully used since 2007 to understand the fluid behavior and estimate bypassed oil areas and had helped to take decisions, such as drilling development wells on a not drained area or to understand the water saturation increasing in wells. Initially was made a 4D seismic modeling to helped interpret time-lapse anomalies seen in the field, was identify approximately a 4% P-impedance contrast difference between oil and brine sands, which suggests that it may be possible to discriminate between oil sands and brine sands in 3D as well as 4D data. Further the two 4Ds data were interpreted in its respective period, generating important decisions for the field. In this paper we compares both results (S4D1 and S4D2) through its anomaly and NRMS maps indicating the possibility of use seismic not 4D dedicated to obtain time-lapse information.