Zero-Offset VSP Monitoring of CO₂ Storage: Impedance Inversion and Wedge Modelling at the Ketzin Pilot Site

Figure 8

Comparison of zero-offset VSP with 3D surface seismic. A detail of the 3D surface seismic inline 1172, which crosses the observation well Ktzi202 (Figure 2) is shown. The traces of the measured and modelled VSP are plotted side by side and inserted at the intersection of inline 1172 with the well. From top to bottom baseline, repeat and difference (repeat minus baseline) of 3D surface seismic and VSP are shown. Consistent phases of 3D surface seismic and zero-offset VSP are marked with diamonds. The VSP data of the left column is bandpass filtered with corner frequencies of 10–20–80–100 Hz; the VSP data of the right column is bandpass filtered with corner frequencies of 10–20–50–70 Hz. The black lines mark the positions of the K2 (upper line), the top, and the bottom of the reservoir (middle and bottom line).