Is Broadband Land Seismic as Good as Marine Broadband?

To evaluate the potential of modern land seismic capabilities and further improve the seismic value for the mining industry, AngloGold Ashanti (AGA) has acquired a prospect area of 35 km2. The geological objective of this test is to image the formations above and below the Ventersdorp Control Reef (VCR) and down to the carbon leader reef, for depths ranging from 2.7 to 3.8 km. This test was the opportunity to illustrate how dense broadband seismic can significantly improve land seismic imaging. The benefit of a dense acquisition with a broadband source is illustrated on the AGA prospect. We compare a conventional acquisition (SLI 420m, SI 70m, RLI 300m, RI 50m; 10-90 Hz) with a dense acquisition (SLI 50m, SI 50m, RLI 100m, RI 50m; 10-90 Hz) and a dense acquisition with a broadband source (SLI 50m, SI 50m, RLI 100m, RI 50m; 3-160 Hz). The expectations from dense acquisition are confirmed by an outstanding imaging quality for all depth levels, simultaneously for ultra-shallow and ultra-deep targets. This in turn leads to significantly improved depth velocity models for a simultaneous optimal focalization and positioning of the seismic reflections. This leads to a textured image with unprecedented stratigraphic details available for the interpretation.