Integrated 4D seismic, geological and reservoir engineering analysis for understanding fluid migration and salinity effects – Jubarte oilfield, Brazil

Integrated surveillance plays a critical role in the development of oil and gas assets, providing essential insights into reservoir dynamics and enabling optimized field management. In 2012, a Permanent-Reservoir-Monitoring (PRM) system was installed over the deepwater Jubarte oilfield in the Campos basin, offshore Brazil. The PRM pilot project covered approximately 9 Km2 (SE of the field). This study applies an integrated geoscientific and engineering workflow enhancing reservoir characterization and management of the field. The investigation focuses on the RO300 producing zone, a Maastrichtian turbiditic sandstones of the Carapebus Formation. The methodology combines 3D/4D seismic interpretation, seismic attribute analysis, well-log evaluation, stratigraphic and structural mapping, petroelastic modeling, and dynamic reservoir simulation. High quality of the seismic response enables the identification of anomalies related to saturation and water salinity changes. Four classes of 4D seismic anomalies were recognized: (1) hardening at producer wells due to oil-to-water substitution; (2) hardening at injector wells indicating high hydraulic transmissibility across faults; (3) softening caused by salinity contrasts in the injected water; (4) acquisition-related seismic noise. Structural analysis highlighted the influence of relay ramp faults and stratigraphic heterogeneities controlling fluid migration pathways. Water movement within the reservoir occurs through both coning and finger-like patterns, influenced by depositional architecture and rock properties. The integration of 4D seismic anomalies with production and tracer data has improved the geological model and flow simulation accuracy. The results demonstrate the effectiveness of multidisciplinary data integration for monitoring reservoir dynamics and optimization hydrocarbon recovery in geologically complex offshore settings.