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A new elastic model for ground coupling of geophones with spikes

Drijkoningen, G.G. (author), Rademakers, F. (author), Slob, E.C. (author), Fokkema, J.T. (author)

Ground coupling are terms that describe the transfer from seismic ground motion to the motion of a geophone. In previous models, ground coupling was mainly considered as a disk lying on top of a half-space, not considering the fact that in current practice geophones are spiked and are buried for optimal response. In this paper we introduce a new...

journal article 2006

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Seismic interferometry: Reconstructing the earth's reflection response

Draganov, D.S. (author), Wapenaar, C.P.A. (author), Thorbecke, J.W. (author)

In 1968, Jon Claerbout showed that the reflection response of a 1D acoustic medium can be reconstructed by autocorrelating the transmission response. Since then, several authors have derived relationships for reconstructing Green's functions at the surface, using crosscorrelations of (noise) recordings that were taken at the surface and that...

journal article 2006

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Green's function representations for seismic interferometry

Wapenaar, C.P.A. (author), Fokkema, J.T. (author)

The term seismic interferometry refers to the principle of generating new seismic responses by crosscorrelating seismic observations at different receiver locations. The first version of this principle was derived by Claerbout (1968), who showed that the reflection response of a horizontally layered medium can be synthesized from the...

journal article 2006

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Imaging of multiple reflections

Berkhout, A.J. (author), Verschuur, D.J. (author)

Current multiple-removal algorithms in seismic processing use either differential moveout or predictability. If the differential moveout between primaries and multiples is small, prediction is the only option available. In the last decade, multidimensional prediction-error filtering by weighted convolution, such as surface-related multiple...

journal article 2006

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Spurious multiples in seismic interferometry of primaries

Snieder, R. (author), Wapenaar, C.P.A. (author), Larner, K. (author)

Seismic interferometry is a technique for estimating the Green's function that accounts for wave propagation between receivers by correlating the waves recorded at these receivers. We present a derivation of this principle based on the method of stationary phase. Although this derivation is intended to be educational, applicable to simple media...

journal article 2006

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A new iterative solver for the time-harmonic wave equation

Riyanti, C.D. (author), Erlangga, Y.A. (author), Plessix, R.E. (author), Mulder, W.A. (author), Vuik, C. (author), Oosterlee, C. (author)

The time-harmonic wave equation, also known as the Helmholtz equation, is obtained if the constant-density acoustic wave equation is transformed from the time domain to the frequency domain. Its discretization results in a large, sparse, linear system of equations. In two dimensions, this system can be solved efficiently by a direct method. In...

journal article 2006

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Plane-wave depth migration

Stoffa, P.L. (author), Sen, M.K. (author), Seifoullaev, R.K. (author), Pestana, R. (author), Fokkema, J.T. (author)

We present fast and efficient plane-wave migration methods for densely sampled seismic data in both the source and receiver domains. The methods are based on slant stacking over both shot and receiver positions (or offsets) for all the recorded data. If the data-acquisition geometry permits, both inline and crossline source and receiver...

journal article 2006

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Validation of first-order diffraction theory for the traveltimes and amplitudes of propagating waves

Jocker, J. (author), Spetzler, J. (author), Smeulders, D.M.J. (author), Trampert, J. (author)

Ultrasonic measurements of acoustic wavefields scattered by single spheres placed in a homogenous background medium (water) are presented. The dimensions of the spheres are comparable to the wavelength and the wavelength and represent both positive (rubber) and negative (teflon) velocity anomalies with respect to the background medium. The...

journal article 2006

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Recursive prestack depth migration using CFP gathers

Thorbecke, J. (author), Berkhout, A.J. (author)

The common-focus-point technology (CFP) describes prestack migration by focusing in two steps: emission and detection. The output of the first focusing step represents a CFP gather. This gather defines a shot record that represents the subsurface response resulting from a focused source wavefield. We propose applying the recursive shot-record,...

journal article 2006

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Seismic signatures of partial saturation on acoustic borehole modes

Chao, G.E. (author), Smeulders, D.M.J. (author), Van Dongen, M.E.H. (author)

We present an exact theory of attenuation and dispersion of borehole Stoneley waves propagating along porous rocks containing spherical gas bubbles by using the Biot theory. An effective frequency-dependent fluid bulk modulus is introduced to describe the dynamic (oscillatory) behavior of the gas bubbles. The model includes viscous, thermal, and...

journal article 2007

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The dynamics of statics

Turhan Taner, M. (author), Berkhout, A.J. (author), Treitel, S. (author), Kelamis, P.G. (author)

The statics problem, whether short wavelength, long wavelength, residual, or trim, has always been one of the more time-consuming and problematic steps in seismic data processing. We routinely struggle with issues such as poor signal-to-noise (S/N) ratio, cycle skipping, truncated refractors, wavelets with ambiguous first arrival times, etc....

journal article 2007

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General representations for wavefield modeling and inversion in geophysics

Wapenaar, C.P.A. (author)

Acoustic, electromagnetic, elastodynamic, poroelastic, and electroseismic waves are all governed by a unified matrix-vector wave equation. The matrices in this equation obey the same symmetry properties for each of these wave phenomena. This implies that the wave vectors for each of these phenomena obey the same reciprocity theorems. By...

journal article 2007

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Application of a linear finite-frequency theory to time-lapse crosswell tomography in ultrasonic and numerical experiments

Spetzler, J. (author), Sijacic, D. (author), Wolf, K.H.A.A. (author)

Time-lapse seismic monitoring is the geophysical discipline whereby multiple data sets recorded at the same location but at different times are used to locate and quantify temporal changes in the elastic parameters of the subsurface. We validate a time-lapse monitoring method by crosswell tomography using two types of wavefield-modeling...

journal article 2007

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Simulating migrated and inverted seismic data by filtering a geologic model

Toxopeus, G. (author), Thorbecke, J.W. (author), Wapenaar, C.P.A. (author), Petersen, S. (author), Slob, E.C. (author), Fokkema, J.T. (author)

The simulation of migrated and inverted data is hampered by the high computational cost of generating 3D synthetic data, followed by processes of migration and inversion. For example, simulating the migrated seismic signature of subtle stratigraphic traps demands the expensive exercise of 3D forward modeling, followed by 3D migration of the...

journal article 2008

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Assessing estimated velocity-depth models: Finding error bars in tomographic inversion

Chitu, D.A. (author), Al-Ali, M.N. (author), Verschuur, D.J. (author)

In conventional migration velocity analysis methods, a velocity model is estimated that results in flattened events in common-image gathers. However, after this process, no information is available on the accuracy of this velocity model. A statistical analysis of velocity-model parameters is very difficult because of the integrated nature of the...

journal article 2008

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Near-surface attenuation estimation using wave-propagation modeling

El Yadari, N. (author), Ernst, F. (author), Mulder, W. (author)

The effect of the near surface on seismic land data can be so severe that static corrections are insufficient. Full-waveform inversion followed by redatuming may be an alternative, but inversion will work only if the starting model is sufficiently close to the true model. As a first step toward determining a viscoelastic near-surface model, we...

journal article 2008

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Virtual reflector representation theorem (acoustic medium)

Poletto, F. (author), Wapenaar, C.P.A. (author)

The virtual reflector method simulates new seismic signals by processing traces recorded by a plurality of sources and receivers. The approach is based on the crossconvolution of the recorded signals and makes it possible to obtain the Green’s function of virtual reflected signals as if in the position of the receivers (or sources) there were a...

journal article 2009

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Estimating and correcting the amplitude radiation pattern of a virtual source

Van der Neut, J. (author), Bakulin, A. (author)

In the virtual source (VS) method we crosscorrelate seismic recordings at two receivers to create a new data set as if one of these receivers were a virtual source and the other a receiver. We focus on the amplitudes and kinematics of VS data, generated by an array of active sources at the surface and recorded by an array of receivers in a...

journal article 2009

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The concept of double blending: Combining incoherent shooting with incoherent sensing

Berkhout, A.J. (author), Blacquiere, G. (author), Verschuur, D.J. (author)

Seismic surveys are designed so that the time interval between shots is sufficiently large to avoid temporal overlap between records. To economize on survey time, the current compromise is to keep the number of shots to an acceptable minimum. The result is a poorly sampled source domain. We propose to abandon the condition of nonoverlapping shot...

journal article 2009

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Ray-based stochastic inversion of prestack seismic data for improved reservoir characterization

Van der Burg, D. (author), Verdel, A. (author), Wapenaar, C.P.A. (author)

Trace inversion for reservoir parameters is affected by angle averaging of seismic data and wavelet distortion on the migration image. In an alternative approach to stochastic trace inversion, the data are inverted prestack before migration using 3D dynamic ray tracing. This choice makes it possible to interweave trace inversion with Kirchhoff...

journal article 2009