Methods for source-independent Q estimation from microseismic and crosswell perforation shot data in a layered, isotropic viscoelastic medium

摘要

We consider the problem of anelastic full waveform inversion in a multi-layered, isotropic viscoelastic medium from microseismic and cross-hole perforation shots. Usually, the source wavelet is not well known, so we focus on Q estimation techniques that can handle this problem. We revisit the spectral ratio method (SRM) and discuss its domain of applicability. We conclude that SRM can be used for interval Q estimation if the sources and receivers are contained in the same homogeneous layer. To overcome the restrictions of SRM, we consider the more sophisticated source-independent full waveform inversion (SIFWI). We compare three different source-independent misfit functions on synthetic data and show that they can be used for Q estimation in a viscoelastic medium. We use 3-D complex ray theory to implement SIFWI in a layered viscoelastic medium.