Viscoelastic reverse time migration using vertical seismic profile and wavefield separation

2019 ◽  
Author(s):  
Ji Guoqiang ◽  
*Shi Ying ◽  
Zhang Wei
Keyword(s):  
Seismic Profile ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Vertical Seismic Profile ◽  
Time Migration ◽  
Wavefield Separation

Vertical seismic profile Kirchhoff migration with structure dip constraint

2015 ◽  
Vol 3 (3) ◽  
pp. SW51-SW56
Author(s):  
Xiaomin Zhao ◽  
Shengwen Jin
Keyword(s):  
Seismic Profile ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Vertical Seismic Profile ◽  
Depth Migration ◽  
Kirchhoff Migration ◽  
Time Migration ◽  
Migration Imaging ◽  
Imaging Result ◽  
Borehole Seismic

Prestack Kirchhoff depth migration is commonly used in borehole seismic imaging, where there is uneven illumination due to the limitations of the source-receiver geometry. A new vertical seismic profile (VSP) migration/imaging workflow has been established that incorporates the structure-dip information derived from a newly developed structure tensor analysis into the existing VSP Kirchhoff migration/imaging technique. This allows us to better image the structures in the vicinity of a borehole and the far-field dipping events away from the borehole. We tested the workflow with the HESS salt model. The results were compared with those from reverse time migration, which found that Kirchhoff migration combined with structure-dip information not only reduced ambiguities of the imaging result but also allowed for imaging dip structures (e.g., fault) in the far region from the borehole. This allows for imaging dip structures and provides a useful extension of existing VSP imaging capabilities using Kirchhoff migration.

Determination of salt proximity by wave‐field imaging of transmitted energy

Geophysics ◽  
1988 ◽  
Vol 53 (8) ◽  
pp. 1109-1112 ◽  
Author(s):  
George A. McMechan ◽  
Liang‐Zie Hu ◽  
Douglas Stauber
Keyword(s):  
Acoustic Waves ◽  
Seismic Profile ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Vertical Seismic Profile ◽  
Wave Fields ◽  
Time Migration ◽  
Vsp Data ◽  
Field Imaging

Prestack reverse‐time migration for acoustic waves has recently been developed for vertical seismic profile (VSP) data (Chang and McMechan, 1986) and for cross‐hole (CH) data (Hu et al., 1988). Both sets of authors use the same migration software and produce images from the scattered (reflected and diffracted) energy in the recorded wave fields.

Vector-based elastic reverse time migration based on scalar imaging condition

Geophysics ◽  
2017 ◽  
Vol 82 (2) ◽  
pp. S111-S127 ◽  
Author(s):  
Qizhen Du ◽  
ChengFeng Guo ◽  
Qiang Zhao ◽  
Xufei Gong ◽  
Chengxiang Wang ◽  
...  
Keyword(s):  
Alternative Methods ◽  
Polarity Reversal ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
S Wave ◽  
Converted Wave ◽  
Imaging Condition ◽  
Time Migration ◽  
Wavefield Separation ◽  
Wave Modes

The scalar images (PP, PS, SP, and SS) of elastic reverse time migration (ERTM) can be generated by applying an imaging condition as crosscorrelation of pure wave modes. In conventional ERTM, Helmholtz decomposition is commonly applied in wavefield separation, which leads to a polarity reversal problem in converted-wave images because of the opposite polarity distributions of the S-wavefields. Polarity reversal of the converted-wave image will cause destructive interference when stacking over multiple shots. Besides, in the 3D case, the curl calculation generates a vector S-wave, which makes it impossible to produce scalar PS, SP, and SS images with the crosscorrelation imaging condition. We evaluate a vector-based ERTM (VB-ERTM) method to address these problems. In VB-ERTM, an amplitude-preserved wavefield separation method based on decoupled elastic wave equation is exploited to obtain the pure wave modes. The output separated wavefields are both vectorial. To obtain the scalar images, the scalar imaging condition in which the scalar product of two vector wavefields with source-normalized illumination is exploited to produce scalar images instead of correlating Cartesian components or magnitude of the vector P- and S-wave modes. Compared with alternative methods for correcting the polarity reversal of PS and SP images, our ERTM solution is more stable and simple. Besides these four scalar images, the VB-ERTM method generates another PP-mode image by using the auxiliary stress wavefields. Several 2D and 3D numerical examples are evaluated to demonstrate the potential of our ERTM method.

Fractured basement imaging using random-space-shift reverse-time-migration: a vertical seismic profile survey in Bohai Bay Basin, China

Geophysics ◽  
2021 ◽  
pp. 1-37
Author(s):  
Jingjing Zong ◽  
Jizhong Yang ◽  
Arthur Cheng ◽  
Yunyue Elita Li ◽  
Yukai Wo ◽  
...  
Keyword(s):  
Velocity Model ◽  
Seismic Profile ◽  
Radioactive Waste Disposal ◽  
Bohai Bay ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Bohai Bay Basin ◽  
Time Migration ◽  
Basement Rocks ◽  
Clear Delineation

Fractured basements not only are potential reservoirs for hydrocarbon resources but also provide significant storage space for carbon dioxide ( CO2) sequestration and radioactive waste disposal. However, fractured basements are challenging to seismic imaging methods due to the complexities in their fault and fracture networks, strong heterogeneity, highly variable structural dip, and strong impedance contrasts between the basement rocks and the surrounding sediments. We present a case where a walk-away vertical seismic profiling (VSP) survey was conducted at a fractured-basement play located in Bohai Bay Basin, China, to improve the resolution compared to a pre-existing surface seismic profile. Using the advanced random-space-shift (RSS) reverse-time-migration (RTM), we obtain a high-resolution image with a clear delineation of the highly faulted dipping basement. From numerical and field examples, we show that the application of the RSS-RTM improves the final image by mitigating unavoidable errors in the migration velocity model which would otherwise result in an unfocused image using the conventional RTM approach. In addition, we demonstrate the importance of proper wavefield separation using three-component (3C) recordings, which is the key to ensuring the quality of the final image. With an optimized VSP imaging workflow, we provide an enhanced image for the fractured basement to support the geologic interpretations and development decisions.

Pre-Stack Depth Migration of High Resolution Distributed Acoustic Sensing VSP

2021 ◽  
Author(s):  
Herurisa Rusmanugroho ◽  
Makky Sandra Jaya ◽  
M Hafizal Zahir ◽  
M Faizal Rahim
Keyword(s):  
High Resolution ◽  
Fiber Optic ◽  
Seismic Profile ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Acoustic Sensing ◽  
Depth Migration ◽  
Time Migration ◽  
Vsp Data ◽  
Distributed Acoustic Sensing

Abstract The performance of pre-stack depth migration (PSDM) on the fiber optic, distributed acoustic sensing (DAS), vertical seismic profile (VSP) data has rarely been reported. We show the results of PSDM for the fiber optic cables, newly developed and tested at a field in Canada. We apply Kirchhoff migration, Fresnel volume migration and reverse time migration (RTM) to the walkway VSP data to obtain high resolution images of the shallow to deeper structures and provide the performance analysis of the migration methods for the DAS VSP data.

Wavefield separation and polarity reversal correction in elastic reverse time migration

2016 ◽  
Vol 127 ◽  
pp. 56-67 ◽  
Author(s):  
Zhiyuan Li ◽  
Xiaona Ma ◽  
Chao Fu ◽  
Guanghe Liang
Keyword(s):  
Polarity Reversal ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration ◽  
Wavefield Separation
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