We can track these changes by repeating 3D seismic surveys over time to create a time-lapse or "4D” seismic image. The interpretation of 4D seismic data helps ensure optimum and responsible oil and gas recovery from our existing fields.
Time-lapse seismic technologies developed and applied by ExxonMobil, including 4D full wavefield inversion, result in high-definition images of seismic changes that enable us to interpret changes in a reservoir with more certainty. Integrated with conventional field production data and reservoir models, 4D seismic methods help increase the productivity of ExxonMobil’s production assets as a result of the improved decision-making derived from the data.
ExxonMobil has applied 4D seismic technology over a wide range of geographical areas, geological settings and production scenarios – from monitoring water and gas sweep (see image) in our deepwater Angola production wells to the thermal recovery processes used at the Cold Lake heavy oil field in Alberta, Canada. Our experience has demonstrated that 4D seismic methods can improve our understanding of the reservoir by identifying its distinct compartments and mapping the most permeable fluid flow pathways. The data can be used to locate unproduced oil and gas, increasing the efficiency of existing wells and reducing the need for additional wells and drilling.