Detecting fractures using time-lapse 3C-3D seismic data

Zimin Zhang, Donald C. Lawton, Robert R. Stewart

This report presents the interpretation of time-lapse 3C-3D seismic data for fracture detection in a Saskatchewan potash mine. Seismic interpretation of the timelapse 3C-3D surveys saw noticeable amplitude changes and time delay effects at the Dawson Bay and underlying formations in the 2008 survey compared with the 2004 survey, especially on the converted-wave (P-to-S) data. Vp/Vs analysis displayed increasing values on the 2008 survey within a faulted part of the survey area. Seismic curvature attributes were calculated at the top of the Dawson Bay Formation and the mining level. The curvatures also suggest that the fractures are well developed in parts of the Dawson Bay Formation.