Smooth inversion of VSP traveltime data

Geophysics ◽  
1999 ◽  
Vol 64 (3) ◽  
pp. 659-661 ◽  
Author(s):  
Daniel Lizarralde ◽  
Steve Swift
Keyword(s):  
Least Squares ◽  
Waveform Inversion ◽  
Seismic Profile ◽  
Vertical Seismic Profile ◽  
Depth Profiles ◽  
Depth Function ◽  
The Earth ◽  
Damping Parameter ◽  
Damped Least Squares

Vertical seismic profile (VSP) direct arrivals provide an insitu measurement of traveltime with depth into the earth. In this note, we describe a weighted, damped least‐squares inversion of VSP traveltimes for a smooth velocity/depth function that inherently reveals the resolution of the data. Smooth velocity/depth profiles of this type are suitable for migration or as a starting models for waveform inversion or tomography. The application of this inversion is particularly simple, requiring only the value of the damping parameter to be determined, and this value is determined from residual statistics.

Practical concept of traveltime inversion of simulated P-wave vertical seismic profile data in weak to moderate arbitrary anisotropy

Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. C107-C123
Author(s):  
Ivan Pšenčík ◽  
Bohuslav Růžek ◽  
Petr Jílek
Keyword(s):  
Waveform Inversion ◽  
Anisotropic Media ◽  
Compressional Wave ◽  
Seismic Profile ◽  
P Wave ◽  
Source Distribution ◽  
S Wave ◽  
Vertical Seismic Profile ◽  
Weak Anisotropy ◽  
Traveltime Inversion

We have developed a practical concept of compressional wave (P-wave) traveltime inversion in weakly to moderately anisotropic media of arbitrary symmetry and orientation. The concept provides sufficient freedom to explain and reproduce observed anisotropic seismic signatures to a high degree of accuracy. The key to this concept is the proposed P-wave anisotropy parameterization (A-parameters) that, together with the use of the weak-anisotropy approximation, leads to a significantly simplified theory. Here, as an example, we use a simple and transparent formula relating P-wave traveltimes to 15 P-wave A-parameters describing anisotropy of arbitrary symmetry. The formula is used in the inversion scheme, which does not require any a priori information about anisotropy symmetry and its orientation, and it is applicable to weak and moderate anisotropy. As the first step, we test applicability of the proposed scheme on a blind inversion of synthetic P-wave traveltimes generated in vertical seismic profile experiments in homogeneous models. Three models of varying anisotropy are used: tilted orthorhombic and triclinic models of moderate anisotropy (approximately 10%) and an orthorhombic model of strong anisotropy (>25%) with a horizontal plane of symmetry. In all cases, the inversion yields the complete set of 15 P-wave A-parameters, which make reconstruction of corresponding phase-velocity surfaces possible with high accuracy. The inversion scheme is robust with respect to noise and the source distribution pattern. Its quality depends on the angular illumination of the medium; we determine how the absence of nearly horizontal propagation directions affects inversion accuracy. The results of the inversion are applicable, for example, in migration or as a starting model for inversion methods, such as full-waveform inversion, if a model refinement is desired. A similar procedure could be designed for the inversion of S-wave traveltimes in anisotropic media of arbitrary symmetry.

Characterization of a carbonate reservoir using elastic full‐waveform inversion of vertical seismic profile data

2020 ◽  
Vol 68 (6) ◽  
pp. 1944-1957 ◽  
Author(s):  
Eric M. Takam Takougang ◽  
Mohammed Y. Ali ◽  
Youcef Bouzidi ◽  
Fateh Bouchaala ◽  
Akmal A. Sultan ◽  
...  
Keyword(s):  
Waveform Inversion ◽  
Seismic Profile ◽  
Carbonate Reservoir ◽  
Full Waveform Inversion ◽  
Profile Data ◽  
Vertical Seismic Profile ◽  
Full Waveform

Synthetic vertical seismic profile

Geophysics ◽  
1981 ◽  
Vol 46 (6) ◽  
pp. 880-891 ◽  
Author(s):  
K. Dautenhahn Wyatt
Keyword(s):  
Seismic Profile ◽  
Synthetic Seismogram ◽  
Domain Model ◽  
Vertical Seismic Profile ◽  
Seismic Section ◽  
The Earth ◽  
Sonic Log ◽  
Wave Propagation Problem ◽  
Layering Effect ◽  
Insight Into

A time‐domain model has been developed for calculation of a synthetic vertical seismic profile (SVSP) from a sonic log recorded in a borehole. The SVSP has proven to be extremely useful in the interpretation of seismic data since it allows the interpreter to analyze the propagation of the source pulse through the earth in depth as well as time. Previously, the synthetic seismogram technique allowed analysis of the earth’s response to the source pulse at the surface only. However, the development of the SVSP allows insight into the entire wave propagation problem since the calculation shows the response of the earth to the source pulse at any depth point in the subsurface. For example, the synthetic seismogram can be used to identify an event on the seismic section as a multiple, whereas, the SVSP cannot only identify a multiple, but can also show which path the source pulse took through the earth layers to create the multiple. The SVSP can also be used to analyze the change in character of the source pulse due to the layering effect of the earth, for example, effects of a thin bed sequence; to study amplitude variations due to transmission losses; and to examine the effects of different source pulse bandwidths on the final surface seismogram, etc. As interpreters gain experience in analyzing the SVSP, many more applications are expected to appear.

1D viscoelastic waveform inversion of zero-offset vertical seismic profile data

2021 ◽  
Author(s):  
Yu Chen ◽  
Takashi Mizuno ◽  
Pierre Bettinelli ◽  
Joël Le Calvez
Keyword(s):  
Waveform Inversion ◽  
Seismic Profile ◽  
Profile Data ◽  
Vertical Seismic Profile ◽  
Zero Offset

scholarly journals Imaging vertical structures using Marchenko methods with vertical seismic-profile data

Geophysics ◽  
2020 ◽  
Vol 85 (2) ◽  
pp. S103-S113 ◽  
Author(s):  
Angus Lomas ◽  
Satyan Singh ◽  
Andrew Curtis
Keyword(s):  
Synthetic Data ◽  
Arbitrary Point ◽  
Seismic Profile ◽  
Single Scattering ◽  
Variable Density ◽  
Vertical Seismic Profile ◽  
The Earth ◽  
Imaging Result ◽  
Fault Structures ◽  
Internal Multiples

Marchenko methods use seismic data acquired at or near the surface of the earth to estimate seismic signals as if the receiver (now a virtual receiver) was at an arbitrary point inside the subsurface of the earth. This process is called redatuming, and it is central to subsurface imaging. Marchenko methods estimate the multiply scattered components of these redatumed signals, which is not the case for most other redatuming techniques that are based on single-scattering assumptions. As a result, images created using Marchenko redatumed signals contain a reduction in the artifacts that usually contaminate migrated seismic images due to improper handling of internal multiples. We exploit recent theoretical advances that enable virtual sources and virtual receivers to be placed at arbitrary points inside the subsurface as a means to incorporate vertical seismic profile (VSP) data into Marchenko methods. The advantage of including this type of data is that the additional acquisition boundary increases subsurface illumination, which in turn enables vertical interfaces and steeply dipping structures to be imaged. We develop this methodology using two synthetic data sets. The first is created using a simple variable density but constant velocity subsurface model. In this example, we find that our newly devised VSP Marchenko imaging methodology enables imaging of horizontal and vertical structures and that optimal results are achieved by combining these images with those created using standard Marchenko imaging. A second example demonstrates that the method can be applied to more realistic subsurface structures, in this case a modified version of the Marmousi 2 model. We determine the applicability of the methods to image fault structures with the final imaging result containing reduced contamination due to internal multiples and an improvement in the imaging of fault structures when compared to other standard imaging methods alone.

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