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Schakel, M.D. (author), Smeulders, D.M.J. (author), Slob, E.C. (author), Heller, H.K.J. (author)
A full-waveform seismoelectric numerical model incorporating the directivity pattern of a pressure source is developed. This model provides predictions of coseismic electric fields and the electromagnetic waves that originate from a fluid/porous-medium interface. An experimental setup in which coseismic electric fields and interface responses...
journal article 2011
document
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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Van der Neut, J.R. (author), Thorbecke, J.W. (author), Mehta, K. (author), Slob, E.C. (author), Wapenaar, C.P.A. (author)
Various researchers have shown that accurate redatuming of controlled seismic sources to downhole receiver locations can be achieved without requiring a velocity model. By placing receivers in a horizontal or deviated well and turning them into virtual sources, accurate images can be obtained even below a complex near-subsurface. Examples...
journal article 2011
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Wapenaar, C.P.A. (author), Draganov, D.S. (author), Snieder, R. (author), Campman, X. (author), Verdel, A. (author)
Seismic interferometry involves the crosscorrelation of responses at different receivers to obtain the Green's function between these receivers. For the simple situation of an impulsive plane wave propagating along the x-axis, the crosscorrelation of the responses at two receivers along the x-axis gives the Green's function of the direct wave...
journal article 2010
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Vogelaar, B. (author), Smeulders, D.M.J. (author), Harris, J. (author)
Seismic effects of a partially gas-saturated subsurface have been known for many years. For example, patches of nonuniform saturation occur at the gas-oil and gas-water contacts in hydrocarbon reservoirs. Open-pore boundary conditions are applied to the quasi-static Biot equations of poroelasticity to derive an exact analytic expression of the...
journal article 2010
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Garcia, R.F. (author), Bruinsma, S. (author), Lognonné, P. (author), Doornbos, E.N. (author), Cachoux, F. (author)
The first in situ sounding of a post-seismic infrasound wavefront is presented, using data from the GOCE mission. The atmospheric infrasounds following the great Tohoku earthquake (on 11 March 2011) induce variations of air density and vertical acceleration of the GOCE platform. These signals are detected at two positions along the GOCE orbit...
journal article 2013
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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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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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Wapenaar, C.P.A. (author), Slob, E.C. (author), Snieder, R. (author), Curtis, A. (author)
In the 1990s, the method of time-reversed acoustics was developed. This method exploits the fact that the acoustic wave equation for a lossless medium is invariant for time reversal. When ultrasonic responses recorded by piezoelectric transducers are reversed in time and fed simultaneously as source signals to the transducers, they focus at the...
journal article 2010
document
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
document
El Allouche, N. (author), Drijkoningen, G.G. (author), Versteeg, W. (author), Ghose, R. (author)
Seismic waves converted from compressional to shear mode in the shallow subsurface can be useful not only for obtaining shear-wave velocity information but also for improved processing of deeper reflection data. These waves generated at deep seas have been used successfully in hydrocarbon exploration; however, acquisition of good-quality...
journal article 2011
document
Draganov, D.S. (author), Campman, X. (author), Thorbecke, J.W. (author), Verdel, A. (author), Wapenaar, C.P.A. (author)
One application of seismic interferometry is to retrieve the impulse response (Green's function) from crosscorrelation of ambient seismic noise. Various researchers show results for retrieving the surface-wave part of the Green's function. However, reflection retrieval has proven more challenging. We crosscorrelate ambient seismic noise,...
journal article 2009
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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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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
document
Van Groenestijn, G.J.A. (author), Verschuur, D.J. (author)
ost wave-equation-based multiple removal algorithms are based on prediction and subtraction of multiples. Especially for shallow water, the prediction strongly relies on a correct interpolation of the missing near offsets. The subtraction of predicted multiples from the data can easily lead to the distortion of primaries if primaries and...
journal article 2009
document
Trani, M. (author), Arts, R. (author), Leeuwenburgh, O. (author), Brouwer, J. (author)
A reliable estimate of reservoir pressure and fluid saturation changes from time-lapse seismic data is difficult to obtain. Existing methods generally suffer from leakage between the estimated parameters. We propose a new method using different combinations of time-lapse seismic attributes based on four equations: two expressing changes in...
journal article 2011
document
Zhubayev, A. (author), Ghose, R. (author)
A careful look into the pertinent models of poroelasticity reveals that in water-saturated sediments or soils, the seismic (P and S wave) velocity dispersion and attenuation in the low field-seismic frequency band (20–200 Hz) have a contrasting behavior in the porosity-permeability domain. Taking advantage of this nearly orthogonal behavior, a...
journal article 2012
document
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
document
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
document
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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