PP- and PS-Wave Effective Q Scanning and Migration Based on the S-Transform

Abstract

Compared with PP-wave data, multicomponent seismic data have obvious advantages in describing complex geological structures during exploration. However, seismic energy is absorbed and dissipated by anelastic subsurface media during wave propagation, which makes seismic imaging more challenging, especially for PS-waves. In this article, we develop a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -compensation method for both PP- and PS-waves based on the S-transform called <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> -compensated prestack time migration (PSTM). Our migration approach has two key steps. First, we use a dip-angle model to optimize the migration aperture; consequently, the predominant diffraction energy from the Fresnel zones is located appropriately. Second, we use effective <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> parameters to compensate for both PP- and PS-wave attenuation along the seismic wave propagation paths during migration. In addition, we propose some strategies for establishing the dip-angle model, estimating the effective <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$ </tex-math></inline-formula> values and matching PP- and PS-wave events. Furthermore, applications to synthetic and field data demonstrate that our migration method effectively recovers the amplitude and phase of seismic waves, so high-resolution migration sections are obtained.