Amplitude-preserving imaging of aliased data using preconditioned Kirchhoff least-squares depth migration.

摘要

Kirchhoff migration is still the most popular imaging algorithm because it easily handles irregular geometries that occur due permitting limitations and surface obstacles. However, if not properly interpolated, irregular geometries also hinder proper amplitude preservation. Preconditioned least-squares migration (PLSM) offers an alternative to 5D interpolation and provides an approximation to Earth's reflectivity that resembles the inverse of seismic modeling. PLSM can also be viewed as an interpolation method based on the subsurface velocity-depth model. The impact of PSLM on final stacked results is minimal, with the main advantage being clean prestack gathers for subsequent AVO and AVAz analysis. Other potential uses of PLSM include regularization of data prior to RTM, as well as a component of diffraction imaging. The main disadvantage of the method is the increase in computational time by a factor of 6-12.