On: “Vertical seismic profiling: Separation of upgoing and downgoing acoustic waves in a stratified medium” by B. Seeman and L. Horowicz (GEOPHYSICS, 48, 555–568, May 1983)

Geophysics ◽  
1986 ◽  
Vol 51 (5) ◽  
pp. 1148-1149
Author(s):  
S. D. Stainsby ◽  
M. H. Worthington
Keyword(s):  
Acoustic Waves ◽  
Sampling Interval ◽  
Stratified Medium ◽  
Time Shift ◽  
Reference Level ◽  
Seismic Profiling ◽  
Vertical Seismic Profiling ◽  
Cutoff Frequencies ◽  
The Earth ◽  
Vsp Data

Seeman and Horowicz devised an elegant procedure for the separation of upgoing and downgoing waves in VSP data. Their method is based upon a least‐squares solution of the frequency‐domain equations which relate the upgoing and downgoing signals at a reference level to the observed signals at other levels in the Earth. The coefficients of these equations are time‐shift operations. Unfortunately, for frequencies [Formula: see text] where δt is the vertical time sampling interval, the denominator of the solution equations is zero. For this reason the authors only applied the method over a passband: [Formula: see text] where the cutoff frequencies [Formula: see text] and [Formula: see text] are chosen to reflect the useful frequency band of the signal.

Separation of frequency-dependent scattering and inelastic absorption by waveform inversion of VSP data constrained by well logs

2019 ◽  
pp. 94-97
Author(s):  
A. S. Pirogova
Keyword(s):  
Seismic Waves ◽  
Waveform Inversion ◽  
Seismic Attenuation ◽  
Well Log ◽  
Frequency Dependent ◽  
Seismic Profiling ◽  
Vertical Seismic Profiling ◽  
The Earth ◽  
Two Factors ◽  
Vsp Data

The paper presents an approach to estimation of frequency-dependent attenuation of seismic waves propagating in the earth subsurface. The approach is based on the waveform inversion of vertical seismic profiling data acquired in a borehole. Incorporation of well log data (in particular, sonic and density logs) in the forward modelling routine allows for separation of two factors that cause frequency-dependent seismic attenuation. In particular, the inversion facilitates separation of 1D scattering versus inelastic absorption in the horizontally layered subsurface.

Calculate Formation Velocity from Vertical Seismic Profiling Data

2014 ◽  
Vol 599-601 ◽  
pp. 639-642
Author(s):  
Jun Zhou ◽  
Chun Hui Xie ◽  
Peng Yang
Keyword(s):  
Random Errors ◽  
Seismic Profiling ◽  
Interval Velocity ◽  
Vertical Seismic Profiling ◽  
Long Offset ◽  
Vsp Data ◽  
Velocity Information

Extracting interval velocity is one of important applications of VSP data. Also, imaging of VSP data requires accurate velocity information. Two kinds of algorithms on the assumption of straight-ray and curve-ray are employed to calculate interval velocity respectively. Comparison of the extracted velocity from the two methods above with real velocity shows that both methods are suitable for VSP data recorded in the vicinity of well, while the algorithm derived from straight-ray fails in the long-offset. Moreover, the curve-ray is more reliable when there are some random errors due to the first arrivals picking.

Analysis and removal of multiply scattered tube waves

Geophysics ◽  
2000 ◽  
Vol 65 (3) ◽  
pp. 745-754 ◽  
Author(s):  
Gérard C. Herman ◽  
Paul A. Milligan ◽  
Qicheng Dong ◽  
James W. Rector
Keyword(s):  
Wave Field ◽  
Large Amplitude ◽  
Data Set ◽  
Impedance Function ◽  
Seismic Profiling ◽  
Vertical Seismic Profiling ◽  
Total Data ◽  
Vsp Data ◽  
Tube Wave

Because of irregularities in or near the borehole, vertical seismic profiling (VSP) or crosswell data can be contaminated with scattered tube waves. These can have a large amplitude and can interfere with weaker upcoming reflections, destroying their continuity. This type of organized noise cannot always be removed with filtering methods currently in use. We propose a method based on modeling the scattered tube‐wave field and then subtracting it from the total data set. We assume that the scattering occurs close to the borehole axis and therefore use a 1-D impedance function to characterize borehole irregularities. Estimation of this impedance function is one of the first steps. Our method also accounts for multiply scattered tube waves. We apply the method to an actual VSP data set and conclude that the continuity of reflected, upcoming events improves significantly in a washout zone.

Correlation between seismic diffractions extracted from vertical seismic profiling data and borehole logging in a carbonate environment

2015 ◽  
Vol 3 (2) ◽  
pp. T121-T129 ◽  
Author(s):  
Alexander Klokov ◽  
Damir Irkabaev ◽  
Osareni C. Ogiesoba ◽  
Nail Munasypov
Keyword(s):  
Joint Analysis ◽  
Seismic Attribute ◽  
Data Set ◽  
Borehole Logging ◽  
Seismic Profiling ◽  
Vertical Seismic Profiling ◽  
Fluid Saturation ◽  
Attribute Analysis ◽  
Vsp Data ◽  
Tectonic Dislocations

Seismic diffractions may play an important role in seismic interpretation because they characterize geologic objects that might not be visible for conventional seismic attribute analysis. Diffractivity may be caused by, and consequently may define, tectonic dislocations (faults and fractures), lithologic variations, and fluid saturation within rocks. We have tied seismic diffractions extracted from vertical seismic profiling (VSP) data and borehole logging, from which we recognized the reasons that were responsible for diffractivity of the strata. First, we processed a multisource multicomponent VSP data set to extract seismic diffractions and constructed diffraction images of the strata for all three of the VSP data components. Then, we performed joint analysis of well logs and diffractions to obtain petrophysical attributes associated with diffraction images. We divided the rock succession into several units, which have different diffraction properties. We identified compacted rock, alternating intervals, isolated fractured zones, and fluid-saturated layers.

THE USE OF VSP TECHNIQUES IN FIELD EVALUATION

1986 ◽  
Vol 26 (1) ◽  
pp. 226
Author(s):  
R.L. Ireson
Keyword(s):  
Seismic Data ◽  
Mode Conversion ◽  
Field Evaluation ◽  
Scalar Wave ◽  
Seismic Profiling ◽  
Vertical Seismic Profiling ◽  
Vsp Data ◽  
Reservoir Porosity ◽  
Deconvolution Techniques ◽  
Inversion Techniques

Vertical Seismic Profiling (VSP) techniques have been developed which have found application in the development and production of hydrocarbons as well as in exploration.A VSP is initiated by outlining the objectives of the survey and, using a model of the geology in the vicinity of the borehole, applying inversion techniques to determine the VSP method best suited to provide the required data. Reflection coverage, critical refractions, and mode conversion data (using 3-component geophones) can be used to obtain a structural, lithologic, and petrophysical interpretation.Structural interpretations using recently developed migration techniques based on the scalar wave equation can now provide images of the sub-surface which are superior to those obtained using previous ray-trace schemes.Acoustic impedance estimates from VSP surveys processed with deterministic deconvolution techniques and optimal amplitude recovery to obtain maximum temporal resolution can be more accurate than those obtained from surface seismic data. Offset VSP data can also give an estimate of reservoir porosity variations away from the borehole.

First-break vertical seismic profiling tomography for Vinton Salt Dome

Geophysics ◽  
2006 ◽  
Vol 71 (3) ◽  
pp. U29-U36 ◽  
Author(s):  
Hua-wei Zhou
Keyword(s):  
A Priori ◽  
Salt Dome ◽  
Data Set ◽  
Velocity Anisotropy ◽  
Seismic Profiling ◽  
Velocity Models ◽  
Vertical Seismic Profiling ◽  
Vsp Data ◽  
Multiscale Inversion ◽  
Sonic Logs

Building laterally depth-varying velocity models for vertical seismic profiling (VSP) imaging is challenging because of the narrow ray-angle coverage of VSP data, especially if only first arrivals are used. This study explores the potential of a new deformable-layer tomography (DLT) for building velocity models with a VSP data set acquired over the Vinton salt dome in southwestern Louisiana. The DLT method uses first breaks to constrain the geometry of velocity interfaces from an initial model of flat, constant-velocity layers parameterized using a priori geologic and geophysical information. A progressive multiscale inversion loop gradually updates the interface geometry. The final solution model, containing 3D geometry, is well supported by resolution and reliability tests and closely matches the long-wavelength trends of area sonic logs. The presence of velocity anisotropy is also indicated.

The O’Doherty‐Anstey formula and localization of seismic waves

Geophysics ◽  
1993 ◽  
Vol 58 (5) ◽  
pp. 736-740 ◽  
Author(s):  
Serguei A. Shapiro ◽  
Holger Zien
Keyword(s):  
Multiple Scattering ◽  
Seismic Waves ◽  
Seismic Attenuation ◽  
Adequate Description ◽  
Amplitude Variation ◽  
Amplitude Variation With Offset ◽  
Seismic Profiling ◽  
Seismic Amplitude ◽  
Vertical Seismic Profiling ◽  
Vsp Data

Angle (or offset) dependent effects of scattering in finely layered media can be observed and analyzed or must be compensated for in vertical seismic profiling data (VSP‐ data), crosshole observations, or seismic amplitude variation with offset (AVO) measurements. Moreover, the adequate description of multiple scattering is important for the study of seismic attenuation in sediments and for the design of inversion procedures.

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