Multi‐scale aspects of wave‐equation reflection tomography

2006 ◽  
Author(s):  
Maarten V. de Hoop ◽  
Robert D. van der Hilst ◽  
Peng Shen
Keyword(s):  
Wave Equation ◽  
Multi Scale ◽  
Reflection Tomography

Sensitivity Analysis of Wave-equation Tomography: A Multi-scale Approach

2009 ◽  
Vol 16 (4) ◽  
pp. 544-589 ◽  
Author(s):  
Valeriy Brytik ◽  
Maarten V. de Hoop ◽  
Mikko Salo
Keyword(s):  
Sensitivity Analysis ◽  
Wave Equation ◽  
Multi Scale

Use of refraction, reflection, and wave-equation-based tomography for imaging beneath shallow gas: A Trinidad field data example

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. VE281-VE289 ◽  
Author(s):  
Nurul Kabir ◽  
Uwe Albertin ◽  
Min Zhou ◽  
Vishal Nagassar ◽  
Einar Kjos ◽  
...  
Keyword(s):  
Wave Equation ◽  
Velocity Field ◽  
Velocity Model ◽  
Surface Velocity ◽  
Low Velocity ◽  
Shallow Gas ◽  
Near Surface ◽  
Velocity Anomaly ◽  
Refraction Tomography ◽  
Reflection Tomography

Shallow localized gas pockets cause challenging problems in seismic imaging because of sags and wipe-out zones they produce on imaged reflectors deep in the section. In addition, the presence of shallow gas generates strong surface-related and interbed multiples, making velocity updating very difficult. When localized gas pockets are very shallow, we have limited information to build a near-surface velocity model using ray-based reflection tomography alone. Diving-wave refraction tomography successfully builds a starting model for the very shallow part. Usual ray-based reflection tomography using single-parameter hyperbolic moveout might need many iterations to update the deeper part of the velocity model. In addition, the method generates a low-velocity anomaly in the deeper part of the model. We present an innovative method for building the final velocity model by combining refraction, reflection, and wave-equation-based tomography. Wave-equation-based tomography effectively generates a detailed update of a shallow velocity field, resolving the gas-sag problem. When applied as the last step, following the refraction and reflection tomography, it resolves the gas-sag problem but fails to remove the low-velocity anomaly generated by the reflection tomography in the deeper part of the model. To improve the methodology, we update the shallow velocity field using refraction tomography followed by wave-equation tomography before updating the deeper part of the model. This step avoids generating the low-velocity anomaly. Refraction and wave-equation-based tomography followed by reflection tomography generates a simpler velocity model, giving better focusing in the deeper part of the image. We illustrate how the methodology successfully improves resolution of gas anomalies and significantly reduces gas sag from an imaged section in the Greater Cassia area, Trinidad.

scholarly journals The acoustic 2-D wave equation in multi-scale transform domains

2019 ◽  
Author(s):  
M. Henriques ◽  
G. Corso ◽  
J. Freitas ◽  
F. Moura ◽  
L. Lucena
Keyword(s):  
Wave Equation ◽  
Multi Scale ◽  
Transform Domains ◽  
D Wave

scholarly journals Wave-equation reflection tomography: annihilators and sensitivity kernels

2006 ◽  
Vol 167 (3) ◽  
pp. 1332-1352 ◽  
Author(s):  
Maarten V. de Hoop ◽  
Robert D. van der Hilst ◽  
Peng Shen
Keyword(s):  
Wave Equation ◽  
Reflection Tomography
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