Seismic anisotropy in exploration and reservoir characterization: An overview

TLDR

Recent advances in parameter estimation and seismic processing now enable the incorporation of anisotropic models—particularly vertical and tilted transverse isotropy—into velocity fields used in prestack depth migration. This review surveys current modeling, processing, and inversion techniques for anisotropic media and highlights future trends toward lower‑symmetry anisotropy as data acquisition improves. Key topics covered include optimal parameterization, body‑wave modeling, P‑wave velocity analysis and imaging, processing in the [Formula] domain, VSP‑based anisotropy estimation, wide‑azimuth moveout inversion, AVO analysis, shear‑wave processing, and fracture characterization. Advancing inversion and processing for realistic anisotropic models will enhance lithology discrimination, fracture detection, and time‑lapse seismology.

Abstract

Recent advances in parameter estimation and seismic processing have allowed incorporation of anisotropic models into a wide range of seismic methods. In particular, vertical and tilted transverse isotropy are currently treated as an integral part of velocity fields employed in prestack depth migration algorithms, especially those based on the wave equation. We briefly review the state of the art in modeling, processing, and inversion of seismic data for anisotropic media. Topics include optimal parameterization, body-wave modeling methods, P-wave velocity analysis and imaging, processing in the [Formula: see text] domain, anisotropy estimation from vertical-seismic-profiling (VSP) surveys, moveout inversion of wide-azimuth data, amplitude-variation-with-offset (AVO) analysis, processing and applications of shear and mode-converted waves, and fracture characterization. When outlining future trends in anisotropy studies, we emphasize that continued progress in data-acquisition technology is likely to spur transition from transverse isotropy to lower anisotropic symmetries (e.g., orthorhombic). Further development of inversion and processing methods for such realistic anisotropic models should facilitate effective application of anisotropy parameters in lithology discrimination, fracture detection, and time-lapse seismology.