A Plane Wave Depth Migration Method for Pre-Stack Seismic Data

One-way wavefield extrapolation methods are used routinely in 3D depth migration algorithms for seismic data. Due to their efficient computer implementations, such one-way methods have become increasingly popular and a wide variety of methods have been introduced. In salt provinces, the migration algorithms must be able to handle large velocity contrasts because the velocities in salt are generally much higher than in the surrounding sediments. This can be a challenge for one-way wavefield extrapolation methods. We present a depth migration method using one-way propagators within lateral windows for handling the large velocity contrasts associated with salt-sediment interfaces. Using adaptive windowing, we can handle large perturbations locally in a similar manner as the beamlet propagator, thus limiting the impact of the errors on the global wavefield. We demonstrate the performance of our method by applying it to synthetic data from the 2D SEG/EAGE [Formula: see text] salt model and an offshore real data example.

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Two-way wave equation-based depth migration using one-way propagators on a bilayer sensor seismic acquisition system

Geophysics ◽

10.1190/geo2017-0172.1 ◽

2018 ◽

Vol 83 (3) ◽

pp. S271-S278

Author(s):

Jiachun You ◽

Ru-Shan Wu ◽

Xuewei Liu ◽

Pan Zhang ◽

Wengong Han ◽

...

Keyword(s):

Wave Equation ◽

Acoustic Wave ◽

Seismic Data ◽

Second Order ◽

Acquisition System ◽

Initial Condition ◽

Acoustic Wave Equation ◽

Data Set ◽

Depth Migration ◽

Migration Method

Conventional migration uses the seismic data set recorded at a given depth as one initial condition from which to implement wavefield extrapolation in the depth domain. In using only one initial condition to solve the second-order acoustic wave equation, some approximations are used, resulting in the limitation of imaging angles and inaccurate imaging amplitudes. We use an over/under bilayer sensor seismic data acquisition system that can provide the two initial conditions required to make the second-order acoustic wave equation solvable in the depth domain, and we develop a two-way wave equation depth migration algorithm by adopting concepts from one-way propagators, called bilayer sensor migration. In this new migration method, two-way wave depth extrapolation can be achieved with two one-way propagators by combining the wavefields at two different depths. It makes it possible to integrate the advantages of one-way migration methods into the bilayer sensor system. More detailed bilayer sensor migration methods are proposed to demonstrate the feasibility. In the impulse response tests, the propagating angle of the bilayer sensor migration method can reach up to 90°, which is superior to those of the corresponding one-way propagators. To test the performance, several migration methods are used to image the salt model, including the one-way generalized screen propagator, reverse time migration (RTM), and our bilayer sensor migration methods. Bilayer sensor migration methods are capable of imaging steeply dipping structures, unlike one-way propagators; meanwhile, bilayer sensor migration methods can greatly reduce the numbers of artifacts generated by salt multiples in RTM.

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Results of applying depth migration on 3D seismic data in the conditions of Eastern Siberia

Neftyanoe khozyaystvo - Oil Industry ◽

10.24887/0028-2448-2021-4-48-51 ◽

2021 ◽

pp. 48-51

Author(s):

E.A. Danko ◽

◽

A.V. Gaiduk ◽

D.N. Tverdokhlebov ◽

E.I. Goguzeva ◽

...

Keyword(s):

Seismic Data ◽

3D Seismic ◽

Eastern Siberia ◽

Depth Migration ◽

3D Seismic Data

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AVO analysis using horizontal component of seismic data in equivalent offset migration method

10.3997/2352-8265.20140217 ◽

2017 ◽

Author(s):

Tomoaki Tanaka ◽

Hitoshi Mikada ◽

Junichi Takekawa

Keyword(s):

Seismic Data ◽

Horizontal Component ◽

Avo Analysis ◽

Migration Method

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Prestack Kirchhoff depth migration of shallow seismic data

Geophysics ◽

10.1190/1.1444425 ◽

1998 ◽

Vol 63 (4) ◽

pp. 1241-1247 ◽

Cited By ~ 22

Author(s):

Linus Pasasa ◽

Friedemann Wenzel ◽

Ping Zhao

Keyword(s):

Waste Disposal ◽

Seismic Data ◽

Signal To Noise Ratio ◽

Disposal Site ◽

Model Estimation ◽

Waste Disposal Site ◽

Depth Migration ◽

Prestack Migration ◽

Shallow Seismic ◽

Kirchhoff Depth Migration

Prestack Kirchhoff depth migration is applied successfully to shallow seismic data from a waste disposal site near Arnstadt in Thuringia, Germany. The motivation behind this study was to locate an underground building buried in a waste disposal. The processing sequence of the prestack migration is simplified significantly as compared to standard common (CMP) data processing. It includes only two parts: (1) velocity‐depth‐model estimation and (2) prestack depth migration. In contrast to conventional CMP stacking, prestack migration does not require a separation of reflections and refractions in the shot data. It still provides an appropriate image. Our data example shows that a superior image can be achieved that would contain not just subtle improvements but a qualitative step forward in resolution and signal‐to‐noise ratio.

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Leading-order seismic imaging using curvelets

Geophysics ◽

10.1190/1.2785047 ◽

2007 ◽

Vol 72 (6) ◽

pp. S231-S248 ◽

Cited By ~ 59

Author(s):

Huub Douma ◽

Maarten V. de Hoop

Keyword(s):

Seismic Data ◽

Order Approximation ◽

Angular Frequency ◽

Leading Order ◽

Numerical Examples ◽

Depth Migration ◽

Map Migration ◽

Kirchhoff Depth Migration ◽

Homogeneous Media ◽

Spatial Support

Curvelets are plausible candidates for simultaneous compression of seismic data, their images, and the imaging operator itself. We show that with curvelets, the leading-order approximation (in angular frequency, horizontal wavenumber, and migrated location) to common-offset (CO) Kirchhoff depth migration becomes a simple transformation of coordinates of curvelets in the data, combined with amplitude scaling. This transformation is calculated using map migration, which employs the local slopes from the curvelet decomposition of the data. Because the data can be compressed using curvelets, the transformation needs to be calculated for relatively few curvelets only. Numerical examples for homogeneous media show that using the leading-order approximation only provides a good approximation to CO migration for moderate propagation times. As the traveltime increases and rays diverge beyond the spatial support of a curvelet; however, the leading-order approximation is no longer accurate enough. This shows the need for correction beyond leading order, even for homogeneous media.

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Integrated prestack depth migration of vertical seismic profile and surface seismic data from the Rocky Mountain Foothills of southern Alberta, Canada

Geophysics ◽

10.1190/1.1635031 ◽

2003 ◽

Vol 68 (6) ◽

pp. 1782-1791 ◽

Cited By ~ 1

Author(s):

M. Graziella Kirtland Grech ◽

Don C. Lawton ◽

Scott Cheadle

Keyword(s):

Seismic Data ◽

Rocky Mountain ◽

Velocity Model ◽

Seismic Profile ◽

Vertical Seismic Profile ◽

Prestack Depth Migration ◽

Data Set ◽

Depth Migration ◽

Southern Alberta ◽

Vsp Data

We have developed an anisotropic prestack depth migration code that can migrate either vertical seismic profile (VSP) or surface seismic data. We use this migration code in a new method for integrated VSP and surface seismic depth imaging. Instead of splicing the VSP image into the section derived from surface seismic data, we use the same migration algorithm and a single velocity model to migrate both data sets to a common output grid. We then scale and sum the two images to yield one integrated depth‐migrated section. After testing this method on synthetic surface seismic and VSP data, we applied it to field data from a 2D surface seismic line and a multioffset VSP from the Rocky Mountain Foothills of southern Alberta, Canada. Our results show that the resulting integrated image exhibits significant improvement over that obtained from (a) the migration of either data set alone or (b) the conventional splicing approach. The integrated image uses the broader frequency bandwidth of the VSP data to provide higher vertical resolution than the migration of the surface seismic data. The integrated image also shows enhanced structural detail, since no part of the surface seismic section is eliminated, and good event continuity through the use of a single migration–velocity model, obtained by an integrated interpretation of borehole and surface seismic data. This enhanced migrated image enabled us to perform a more robust interpretation with good well ties.

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