Scattered based Marchenko redatuming by inversion

Abstract

Marchenko redatuming is a recently developed framework, which is used to retrieve up- and down going waveforms from an arbitrary depth in the subsurface. For this, the scheme only needs single-sided surface reflection data and a little information about the medium, for example a conventional velocity model. The obtained Green’s function can be used to obtain more detailed images of the subsurface, which is especially important and more difficult for perturbed media, or complex media, e.g. a medium containing a subsalt structure. This research focuses on two new developments in Marchenko calculations: The first is solving the Marchenko system by means of inversion instead of iteration, which has so far been the main solving method. Secondly a newly proposed variation on the Marchenko system is tested. It focuses specifically on perturbed fields, which will have complex-media reflection data. This will result in a more difficult problem to solve. This research uses two example models to show that the Marchenko system can be solved by inversion, and to show that the results of this new construction validate the proposed approach. Both these findings will be useful for further use of the Marchenko scheme, especially when the models become more complex, for example, in heterogeneous and/or variable velocity models.