A Comparison of the Effects of Layering and Attenuation on the Seismic Response of Gas Reservoirs

Summary In this paper, we investigate the relative contributions of layering, viscous attenuation and poroelastic attenuation to the frequency spectrum characteristics of seismic reflections. Our objective is to reproduce frequency anomalies typically observed in seismic reflection data. The results of seismic modeling show that low-frequency anomalies and other frequency anomalies can be explained by a filtering effect caused by a particular pattern of layering in the subsurface formations. The effect of layering is accompanied with significant velocity dispersion, which can be mistaken for the effects of intrinsic attenuation. However, we show that the effect of layering strongly dominates over viscoelastic and poroelastic wave propagation effects.