Q-compensated viscoelastic reverse time migration using mode-dependent adaptive stabilization scheme

Abstract

The [Formula: see text]-compensated viscoelastic reverse time migration ([Formula: see text]-ERTM) method counteracts the subsurface quality-factor ([Formula: see text]) filtering effect for attenuated multicomponent seismic data to produce high-quality migrated images. Compared with [Formula: see text]-compensated viscoacoustic reverse time migration ([Formula: see text]-ARTM), [Formula: see text]-ERTM provides more informative geologic and structural characterization of the subsurface, but it poses greater challenges on viscoelastic wavefield decomposition and stabilization. On the basis of our previously proposed stabilization operator for [Formula: see text]-ARTM, we have developed a mode-dependent adaptive stabilization scheme for [Formula: see text]-ERTM, which has the ability to handle the numerical instability issue arising from viscoelastic compensation. The stabilization scheme exhibits superior properties of time variance and [Formula: see text] dependence over the commonly used low-pass filtering method. In the context of the viscoelastic wave equation with decoupled fractional Laplacians, we have thoroughly investigated the staggered-grid pseudospectral approach for viscoelastic simulation, vector-based wavefield decomposition for imaging, and mode-dependent adaptive stabilization for compensation. These indispensable modules eventually form the whole framework for stable and accurate [Formula: see text]-ERTM. The [Formula: see text]-ERTM results including PP- and PS-images from synthetic and field data sets are provided to verify the feasibility and superiority of our approach in terms of fidelity and stability.