Seismic Wave Migration in Visco‐Acoustic VTI Media: A One‐Way Operator With De Wolf Renormalization Scattering Series Approximation

ABSTRACT

Real earth media cause absorption attenuation and anisotropy. Ignoring these effects leads to amplitude and imaging‐position errors in migration profiles. The classical Born approximation generates large errors under the strong forward accumulative effect of visco‐acoustic VTI (Transversely Isotropic media with a Vertical symmetry axis) media. Therefore, this article integrates the De Wolf approximation with visco‐acoustic VTI media for the first time. We renormalize the Born series using the De Wolf approximation and establish its integral representation for visco‐acoustic VTI media, thereby improving the accuracy of the Born approximation. Following the thin‐slab approximation, the velocity model is divided into several thin slabs, each containing background parameters (velocity, quality factor and anisotropy) and perturbation parameters. Dual‐domain screen approximation migration operators (frequency‐wavenumber and frequency‐space domains) are then constructed for visco‐acoustic VTI media, leading to a prestack migration imaging method based on the De Wolf approximation. Algorithm tests on the Overthrust and Hess models show that the proposed migration operator effectively compensates for amplitude attenuation and corrects anisotropic effects, producing migration results with higher signal‐to‐noise ratio and resolution. The specific effects of viscosity and anisotropy on imaging are explicitly analysed based on comparative data of migration profiles, waveforms and amplitude spectra, further validating the algorithm's effectiveness.