Paper Summary

During the last decades, broadband seismic surveys became more prevalent and for several years this has also been used for time-lapse seismic monitoring of hydrocarbon producing fields or CO2 storage targets. With optimized survey design and dedicated processing sequences, both the monitor acquisition repeatability and the frequency bandwidth of the useful seismic signal at target level are improved. Since the low frequency part of the seismic signal has a direct impact on the reliability of seismic amplitude inversion, this has led to improving relevant 4Dresolution which is crucial during 4D interpretation and integration. In our context of oil field monitoring, we compare base and monitor seismic from standard good quality bandwidth to broadband data. We decoupled the Signal-Noise component of the data from the seismic frequency bandwidth. This permits a more robust estimation of our different 4D attributes. In addition, geostatistical tools have been used to better quantitatively compare conventional and broadband monitor pairs. The final 4D interpretation and integration step takes benefit of the useful bandwidth from the broadband data thereby allowing for easier 4D attribute handling, the possibility to consider lower values of relevant 4D attributes and the computation of a more representative 4D geobody volumes in the allocation matching process. Also, the geobody interpretation on different monitor pairs can help to better precise the effective fluid and pressure pathways due to field production mechanisms.