Benefits of multifocusing stack — A new method of time imaging

Abstract

Summary The multifocusing method consists in stacking seismic data with arbitrary source-receiver distribution according to a new local moveout correction. This moveout correction is based on a local spherical approximation of the reflection wave front in the vicinity of an observation surface. We demonstrate that the multifocusing method does not require any knowledge of the subsurface model and can produce an accurate zero offset section, even in cases of a complex geological structure and low signal-to-noise ratio. The estimated sets of parameters, namely the emergence angle and the wave front curvatures for normal incident and common reflection element waves, which define the local moveout correction, contain important information regarding the subsurface model and may be used for structural and lithological inversion. We illustrate an application of the multifocusing imaging to synthetic data and compare it with conventional NMO + DMO stacking, prestack time and depth migrations.