Estimating Velocity and Attenuation Changes Due to CO2 Saturation Using the Active Doublet Method: A Synthetic Study

Injection and movement/saturation of CO2 in a geological formation will cause changes in seismic velocities and attenuation, which result in changes in seismic-wave scattering and propagation. Accurately estimating seismic velocity and attenuation changes from time-lapse seismograms will provide valuable information about where CO2 moves. We conduct numerical studies of time-lapse seismic responses of CO2 injection with different saturation levels of CO2, using a finite-difference elastic-wave equation scheme. The method has the fourth-order accuracy in space and the second-orde