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.