Attenuation estimation from DAS VSP data of CaMI Field Research Station

Yichuan Wang, Donald C. Lawton

For seismic monitoring injected CO₂ during geologic CO₂ sequestration, it is useful to measure seismic attenuation. Seismic attenuation directly connects to different petrophysical parameters of reservoir rock or CO₂ capture and storage site. We have used an approach for measuring attenuation by iteratively identifying a sparse set of the strongest reflections in the seismic trace and stacking their waveforms. This method is straightforward and requires no sophisticated inverse algorithm. It is data-driven and shows a trade-off between resolution and estimation accuracy. This method is applied to the DAS VSP dataset from the CaMI Field Research Station (FRS) in Newell County, Alberta. High-quality attenuation-quantity cross-sections are obtained. Strong attenuation within the CO₂ injection zone around the CO₂ injection well is observed, which is interpreted as being related to the injected CO₂ at the FRS.