Multifocusing in practice

A new method of seismic time imaging called Multifocusing has been developed and implemented. The multifocusing method is based on the theory of homeomorphic imaging and consists of stacking seismic data with arbitrary source-receiver distribution according to a new local moveout correction. This 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 produces 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 multi-focusing imaging for synthetic and real data and compare it to conventional NMO + DMO stack, prestack time and depth migrations.