High-frequency restoration of surface seismic data - Arcis

Figure 6. Sectional amplitude spectra for seismic inline 85 indicates the extent of frequency enhancement.Figure 7. Seismic crossline 72 before (left) and after (right) HFR.A3D VSP and a coincident 3D surface seismic surveywere recorded around well 8-20 in the Hanna area of centralAlberta, targeting the Lower Mannville formation (Chopra etal., 2002). The well encountered a gross Lower Mannvilleinterval 20.5 m thick and thicker than in adjacent wells 6-20(11.5 m) and 8-21 (7 m). The 3D seismic programs (surface andVSP) were recorded to assist in defining sand presence andporosity development in the Lower Mannville intervalbetween 1300 and 1350 m. The objectives for the 3D VSPrecording were to (a) tie the seismic reflections to lithologyand stratigraphic boundaries; (b) obtain a high frequencyimage around the borehole (the fixed receiver array and itsproximity to the reservoir are expected to improve imagequality); and (c) obtain an improved subsurface velocity model.HFR was run on the seismic data. Figure 5 shows a segmentof seismic inline 85 with and without HFR. Notice the0000 THE LEADING EDGE AUGUST 2003 AUGUST 2003 THE LEADING EDGE 0000