Rock Property Estimation Using Dual-Sensor Streamer Data without Well Constraint - North Sea Jurassic Case Study

Broadband seismic data are becoming increasingly common, with many different methods of producing a broader range of frequencies. Accurately recorded broadband frequencies are of particular use for quantitative interpretation, and can give much improved seismic inversion results (Reiser et al., 2012). In this case study, dual-sensor streamer seismic data is compared with conventional seismic data over Grevling, a Jurassic oil discovery in the Central North Sea. The results of rock property estimation are compared by using an entirely seismic data-driven inversion workflow, i.e. without using any well information as input. The comparison between the two datasets demonstrates that there is highly valuable rock property information in the additional recorded frequencies of the dual-sensor seismic data, in particular the octave gain on the low frequency side at the reservoir level. The dual-sensor seismic data allows a better fluid discrimination within the reservoir and demonstrates a clear trend in the Vp/Vs data directly recorded by the seismic data. The workflow has been validated by comparing the seismic rock properties to an independently derived rock physics model and found to match closely.