Adaptive double-focusing method for source-receiver Marchenko redatuming on field data

We present an adaptive double-focusing method for applying source-receiver Marchenko redatuming to field data. Receiver redatuming is achieved by a first focusing step, where the coupled Marchenko equations are iteratively solved for the oneway Green’s functions. Next, source redatuming is typically performed by a multi-dimensional deconvolution...

Deconvolution and correlation-based interferometric redatuming by wavefield inversion

Seismic interferometry is a method to retrieve Green’s functions for sources (or receivers) where there are only receivers (or sources, respectively). This can be done by correlationor deconvolution-based methods. In this work we present a<br/>new approach to reposition the seismic array from the earth’s surface to an arbitrary datum at depth...

Decomposition of the Green's function using the Marchenko equation

The Marchenko equation can be used to retrieve the Green’s function at depth as a full function or decomposed into its upand downgoing parts. We show that the equation can be rewritten to create a decomposition scheme that can decompose a full wavefield, that was recorded at depth, into its up- and downgoing parts. We show that this can be done...

New method for discriminating 4D time shifts in the overburden and reservoirr

Understanding seismic changes in the subsurface is important for reservoir management and health, safety and environmental (HSE) issues. Typically the changes are interpreted based on the time shifts in seismic time-lapse (4D) data, where sources are at the surface and receivers are either at the surface or in a borehole. With these types of...

From closed-boundary to single-sided homogeneous Green's function representations

The homogeneous Green’s function (i.e., the Green’s function and its time-reversed counterpart) plays an important role in optical, acoustic and seismic holography, in inverse scattering methods, in the field of time-reversal acoustics, in reversetime migration and in seismic interferometry. Starting with the classical closed-boundary...

Beyond Marchenko: Obtaining virtual receivers and virtual sources in the subsurface

By solving the Marchenko equations, the Green’s function can be retrieved between a virtual receiver in the subsurface to points at the surface (no physical receiver is required at the virtual location). We extend the idea of these equations to retrieve the Green’s function between any two points in the subsurface; i.e, between a virtual source...

Electromagnetic Marchenko imaging in 1D for dissipative media

We present a one-dimensional lossless scheme to compute an image of a dissipative medium from two single-sided reflection responses. One reflection response is measured at or above the top reflector of a dissipative medium and the other reflection response is computed as if measured at or above the top reflector of a medium with negative...

Marchenko wavefield redatuming, imaging conditions, and the effect of model errors

Recently, a novel method to redatum the wavefield in the sub-surface from a reflection response measured at the surface has gained interest for imaging primaries in the presence of strong internal multiples. A prerequisite for the algorithm is an accurate and correct estimate of the direct-wave Green's function. However, usually we use an...

An interferometric interpretation of Marchenko redatuming including free-surface multiples

We present an interferometric interpretation of the iterative Marchenko scheme including both free-surface multiples and internal multiples. Cross-correlations are used to illustrate the combination of causal and acausal events that are essential for the process of multiple removal. The first 4 steps in the scheme are discussed in detail, where...

Autofocusing imaging: Imaging with primaries, internal multiples and free-surface multiples

Recent work on autofocusing with the Marchenko equation has shown how the Green's function for a virtual source in the subsurface can be obtained from reflection data. The response to the virtual source is the Green's function from the location of the virtual source to the surface. The Green's function is retrieved using only the reflection...