Paper Summary
The heavy oil reservoirs of the Bentley, Bressay and Kraken (BBK) of East Shetland Platform (ESP) are in close proximity to other highly resistive layers such as the regional Balder Tuff that lies directly above the reservoirs, and a granite intrusion that sits beneath the Bentley discovery. The subsurface geology is complex beneath a shallow water column (90-130m) and provides a good test area in terms of controlled source electromagnetic (CSEM) surveying. Towed streamer EM data acquired in October 2012 show strong EM anomaly over the BBK structures. Using a realistic reservoir model interpreted from seismic data improved the EM modeling results to interpret the measured anomaly. Introduction of non-HC related high-resistivity elements provides more realistic EM modeled responses. The measured data were inverted as a series of 1D inversion for all common mid-points (CMP) along two survey lines to produce transverse resistance, which correspond fairly well with seismically interpreted high-resistivity structures. EM modeled data also indicates that resistive structures can be interpreted even when seismic interpretation is challenging and thus measured EM data can complement seismic data in structural model building. The two techniques integrated together hence provide a more powerful methodology than either technique alone.