Searched for: mods_originInfo_publisher_s%3A%22EAGE%22
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Mulder, W.A. (author)
Recently introduced non-reflecting boundary conditions are numerically exact: the solution on a given domain is the same as a subset of one on an enlarged domain where boundary reflections do not have time to reach the original domain. In 1D with second- or higher-order finite differences, a recurrence relation based on translation invariance...
conference paper 2021
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Mulder, W.A. (author)
Multi-parameter inversion of linear systems appears in many problems. The focus here is on isotropic elastic iterative reverse-time migration for three position-dependent subsurface model parameters, which amounts to data fitting of processed seismic data with synthetics from the Born approximation of the elastic wave equation. In that case, the...
conference paper 2021
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Cupillard, Paul (author), Mulder, W.A. (author), Anquez, Pierre (author), Mazuyer, Antoine (author), Barthélémy, J. (author)
The Earth interior contains heterogeneities at all scales, ranging from pores and mineral grains to major global units. On the contrary, seismic recordings only contain variations larger than the minimum wavelength λmin. The heterogeneities smaller than λmin are naturally smoothed by the wavefield, leading to effective media when inverting...
conference paper 2021
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Lyu, X. (author), Voskov, D.V. (author), Rossen, W.R. (author)
Foam injection is one efficient way to mitigate gravity segregation during CO2 injection into porous media. The effect of gravity segregation on foam propagation in heterogeneous porous media is not yet fully resolved. To assess CO2 foam transport for enhanced oil recovery (EOR) and for CO2 storage processes in heterogeneous reservoirs, an...
conference paper 2021
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Pijnenburg, R. (author), Laumann, S.J. (author), Wessels, R. (author), Maat, G. Ter (author), Armstrong, L.S. (author), Vardon, P.J. (author), Bruhn, D.F. (author), Barnhoorn, A. (author), Wapenaar, C.P.A. (author)
The European Plate Observing System - Netherlands (EPOS-NL) is the Dutch research infrastructure for solid Earth sciences. EPOS-NL is a cluster of large-scale geophysical facilities for research on georesources and geohazards. It is a partnership between Delft University of Technology (TU Delft), the Royal Netherlands Meteorological Institute...
conference paper 2021
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Almobarak, M. (author), van IJsseldijk, J.E. (author), Wapenaar, C.P.A. (author)
Seismic imaging is often used to interpret subsurface formations. However, images obtained by conventional methods are contaminated with internal multiples. The Marchenko method provides the means to obtain multiple-free subsurface images. Due to the high computational cost of the conventional point-source Marchenko imaging method, the less...
conference paper 2021
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Mulder, W.A. (author)
The representation of a force or of a moment point source in a spectral finite-element code for modelling elastic wave propagation becomes fundamentally different in degenerate cases where the source is located on the boundary of an element. This difference is related to the fact that the finite-element basis functions are continuous across...
conference paper 2021
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van der Neut, J.R. (author), Brackenhoff, J. (author), Meles, G. (author), Zhang, L. (author), Slob, E.C. (author), Wapenaar, C.P.A. (author)
Green’s functions in an unknown medium can be retrieved from single-sided reflection data by solving a multidimensional Marchenko equation. This methodology requires knowledge of the direct wavefield throughout the medium, which should include forward-scattered waveforms. In practice, the direct field is often computed in a smooth background...
conference paper 2021
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Li, K. (author), Wolf, K.H.A.A. (author), Rossen, W.R. (author)
By trapping gas, foam can improve the sweep efficiency in enhanced oil recovery. In this study, to understand gas trapping in fractures, we have conducted experiments in a model fracture with a hydraulic aperture of 80 μm. One wall of the fracture is rough, and the other wall is smooth. The fracture is made of two glass plates and the direct...
conference paper 2021
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Slob, E.C. (author), Zhang, L. (author)
The ability to separate primary reflections from multiples is important for making subsurface images. Many existing methods need some form of model information and adaptive subtraction. Marchenko methods have been modified to operate at the acquisition surface. The associated filters can be computed from the reflection response without any model...
conference paper 2020
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Werthmüller, D. (author), Slob, E.C. (author)
Modelling time-domain electromagnetic data with a frequency-domain code requires the computation of many<br/>frequencies for the Fourier transform. This can make it computationally very expensive when compared with timedomain codes. However, it has been shown that frequency-domain codes can be competitive if frequencydependent modelling grids...
conference paper 2020
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Reinicke Urruticoechea, C. (author), Dukalski, M.S. (author), Wapenaar, C.P.A. (author)
Marchenko methods aim to remove all overburden-related internal multiples. The acoustic and elastodynamic formulations observe identical equations, but different physics. The elastodynamic case highlights that the Marchenko method only handles overburden-generated reflections, i.e. forward-scattered transmitted waves (and so-called fast...
conference paper 2020
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Staring, M. (author), Zhang, L. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author)
We have seen many developments in Marchenko equation-based methods for internal multiple attenuation in the past years. Starting from a wave-equation based method that required a smooth velocity model, there are now Marchenko equation-based methods that do not require any model information or user-input. In principle, these methods accurately...
conference paper 2020
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Alfaraj, H.S.A. (author), Brackenhoff, J.A. (author), Wapenaar, C.P.A. (author)
When reflection images are studied, often only the zero-offset reflectivity is considered, however, taking into account the angle-dependent reflectivity can add additional information about the subsurface. This additional information can be used to extract the properties of the subsurface using amplitude variation with offset (AVO) analysis....
conference paper 2020
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van IJsseldijk, J.E. (author), Wapenaar, C.P.A. (author)
The Marchenko method retrieves the responses to virtual sources in the subsurface, accounting for all orders of multiples. The method is based on two integral representations for focusing and Green’s functions. In discretized form these integrals are represented by finite summations over the acquisition geometry. Consequently, the method...
conference paper 2020
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Shoja, S.M. Aydin (author), Meles, G.A. (author), Wapenaar, C.P.A. (author)
The Hessian matrix plays an important role in correct interpretation of the multiple scattered wave fields inside the FWI frame work. Due to the high computational costs, the computation of the Hessian matrix is not feasible. Consequently, FWI produces overburden related artifacts inside the target zone model, due to the lack of the exact...
conference paper 2020
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Brackenhoff, J.A. (author), van IJsseldijk, J.E. (author), Wapenaar, C.P.A. (author)
We consider reflection data that have been subsampled by 70% and use Point-Spread-Functions to reconstruct the original data. The subsampled, original and reconstructed reflection data are used to image the medium of interest with the Marchenko method. The image obtained using the subsampled data shows artifacts caused by internal multiples,...
conference paper 2020
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Meles, G.A. (author), Zhang, L. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author), Slob, E.C. (author)
Seismic images provided by reverse time migration can be contaminated by artefacts associated with the migration of multiples.<br/><br/>Multiples can corrupt seismic images, producing both false positives, i.e. by focusing energy at unphysical interfaces, and false negatives, i.e. by destructively interfering with primaries. Multiple-related...
conference paper 2020
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Slob, E.C. (author), Zhang, L. (author)
Marchenko methods compute a focusing function for a receiver at the acquisition surface and a virtual source in the subsurface. Computing the focusing function requires subsurface information. The method has been modified to operate at the acquisition surface. The focusing function becomes a fundamental wave field as known since many decades....
conference paper 2020
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Abolhassani, S. (author), Slob, E.C. (author), Vossepoel, F.C. (author)
Considering the steadily declining prices in the oil and gas industry, nowadays, the requirement for geophysical information becomes more important in order to get the most out of available reservoirs. Electromagnetic measurements could complement seismic data where it lacks information. The EM response to fluid fill complements the resolving...
conference paper 2020
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