Estimating Overburden-Only Transmission Waveforms from Surface Reflection Data

Abstract

The characterisation of complex overburden structures can be key for seismic imaging in many geologic settings. To this end, one of the main challenges can be the separation of overburden signals from those coming from deeper structures. Here, we present a data-driven, focusing-based approach to extract full-waveform overburden-only transmission responses from surface-acquired
reflection seismic data. Our approach builds on the Marchenko redatuming framework, which is capable of retrieving subsurface fields at depth, containing all internal multiples, from surface reflection data. Intrinsic to the
Marchenko scheme is the retrieval of focusing functions, which by definition are sensitive only to overburden properties. Here, we show that the overburden-only
transmission can be obtained directly by combining the focusing coda, a by-product of Marchenko redatuming, with a model-based reference transmission. Our transmission estimate can be obtained by inversion of the focusing operator, as well as by a numerically stable, series-based iterative scheme.
We present our transmission estimation approach for acoustic and elastic media, and validate both cases using numerical examples. Our examples show
that, within its domain of validity, our series-based transmission estimates quickly converge to the desired transmission responses, with good
accuracy both in terms of kinematics and absolute amplitudes.