Laboratory estimation of fracture compliance of a fluid-filled fracture using AVO response of a nonwelded interface

We explore the potential of multi-angle AVO inversion of P-P and P-S reflections from a fracture to estimate fracture proper- ties. Although AVO analysis of welded interface like geologi- cal layer boundaries is common, the use of AVO variations for nonwelded boundaries like fractures is yet to be investigated. We conduct laboratory experiments...

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...

Reflecting boundary conditions for interferometry by multidimensional deconvolution

In this work we investigate a modification of the formulation of the theory underlying seismic interferometry (SI) by multidimensional deconvolution (MDD). The current formulation, and hence method, relies on separation of waves traveling inward and outward of a volume bounded by receivers. As a consequence, it is predominantly useful when...

Characterization of heterogeneous fracture compliance using multiple reflections coupled with data-driven Green's function retrieval

The spatial heterogeneity along a fracture is a key determinant for fracture-associated hydraulic properties. We propose a new method to estimate the heterogeneous compliance distribution of a fracture from the reflection response at the fracture surface. For this purpose, we formulate a data-driven approach for Green's function retrieval based...

Probing the solution space of an EM inversion problem with a genetic algorithm

In an inversion for the subsurface conductivity distribution using frequency-domain Controlled-Source Electromagnetic data, various amounts of horizontal components may be included. We investigate which combination of components are best suited to invert for a vertical transverse isotropic (VTI) subsurface. We do this by probing the...

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...

On the focusing conditions in time-reversed acoustics, seismic interferometry, and Marchenko imaging

Despite the close links between the fields of time-reversed acoustics, seismic interferometry and Marchenko imaging, a number of subtle differences exist. This paper reviews the various focusing conditions of these methods, the causality/acausality aspects of the corresponding focusing wavefields, and the requirements with respect to...

Non-linear imaging condition to image fractures as non-welded interfaces

Hydraulic properties of a fractured reservoir are often controlled by large fractures. In order to seismically detect and characterize them, a high-resolution imaging method is necessary. We apply a non-linear imaging condition to image fractures, considered as non-welded interfaces. We derive the imaging condition from the general correlation...

A method to suppress spurious multiples in virtual-source gathers retrieved using seismic interferometry with reflection data

Seismic interferometry applied to surface reflection data (with source and receivers at the surface) allows to retrieve virtual-source gathers at the position of receivers, where no source was shot. As a result of the crosscorrelation of all primary and multiple reflections, the virtual-source gathers contain retrieved physical reflections as...

Internal multiple suppression by adaptive Marchenko redatuming

Recently, a novel iterative scheme was proposed to retrieve Green's functions in an unknown medium from its single-sided reflection response and an estimate of the propagation velocity. In Marchenko imaging, these Green's functions are used for seismic imaging with complete wavefields, including internal multiple reflections. In this way, common...

Quality-factor and reflection-coefficient estimation using reflected surface waves

We propose a method for estimating the reflection coefficient of a subvertical boundary and the the quality factor of the medium between a receiver and the subvertical boundary. The method uses surface waves from transient deterministic sources and is inspired by the occurrence of non-physical arrivals in seismic-interferometry results due to...

Iterative separation of blended marine data: Discussion on the coherence-pass filter

n conventional marine acquisition surveys the time intervals between the firing of successive sources are large enough to avoid interference in time. To obtain an efficient survey, the spatial source sampling is therefore often (too) large. How- ever, much attention has been drawn recently to blended ac- quisition designs, where sources are shot...

Separation of blended data by iterative estimation and subtraction of interference noise

Conventional data acquisition practice dictates the existence of sufficient time intervals between the firing of successive sources in the field. However, much attention has been drawn recently to the possibility of shooting in an overlapping fash- ion. Numerous publications have addressed the issue from dif- ferent scopes (denoising,...

Criteria for source and receiver positioning in time-lapse seismic acquisition

The effects of mis-positioning in time-lapse seismics aie studied, focusing on irregular sampling due to receiver mis-positioning and absence of data due to surface obstacles. Wavefield reconstruction is used to regularize data and to reconstruct data where data-gaps are present. The method is tested on time-lapse 2D synthetic and Troll streamer...