Produção Científica



Apresentação
23/03/2012

Uma formulação Bayesiana para inversão conjunta de AVO de dados PP e PS
Sérgio Adriano Moura Oliveira, Fernando Sérgio de Moraes, Anderson Franco e José Caparica. 1º Workshop do INCT-GP (2011)
Apresentação
23/03/2012

Medidas de coerência para análise de velocidade na migração em tempo.
Jonathas da S. Maciel, Jessé C. Costa e Jörg Schleicher.
1º Workshop do INCT-GP (2011)
Apresentação
23/03/2012

Results for three simple sea bed logging antenna models
Allen Q. Howard. JR. 1º Workshop do INCT-GP (2011)
Apresentação
23/03/2012

Recuperação de contornos não convexos de corpos anômalos na tomografia poço a poço em função da presença de ruído
Walter Eugênio de Medeiros, Roberto Hugo Bielschowsky. 1º Workshop do INCT-GP (2011)
Apresentação
23/03/2012

High-order pseudo-analytical method for acoustic wave modeling
Reynam Pestana, Chunlei Chu and Paul L. Stoffa. 1º Workshop do INCT-GP (2011)
Apresentação
23/03/2012

Modelagem Bidimensional do Método Eletromagnético a Multifrequência.
Valdelírio da Silva e Silva, Cícero Roberto Teixeira Régis e Carlos Alberto Dias. 1º Workshop do INCT-GP (2011)
Apresentação
23/03/2012

Fast estimation of common-reflection-surface parameters using local slopes
Lúcio Santos, Jörg Schleicher, Jessé C. Costa, and Amélia Novais. 1º Workshop do INCT-GP (2011)
Apresentação
30/11/2011

3D complex Padé FFD migration: A comparison of splitting techniques
Jessé C. Costa, Débora Mondini, Jörg Schleicher, and Amélia Novais
SEG Expanded Abstracts 30, 4420-4424 (2011)

SUMMARY
Three-dimensional wave-equation migration techniques are quite expensive because of the huge matrices that need to be inverted. Many techniques have been proposed to reduce this cost by splitting the 3D problem into a sequence of 2D problems. We compare the performance of splitting techniques for stable 3D Fourier Finite-Difference (FFD) migration techniques in terms of image quality and computational cost. The FFD methods are complex Pade FFD and FFD plus interpolation, and the compared splitting techniques are two and fourway splitting as well as alternating four-way splitting, i.e., splitting into the coordinate directions at one depth and the diagonal directions at the next level. From numerical examples in homogeneous and inhomogeneous media, we conclude that alternate four-way splitting yields results of the same quality as full four-way splitting at the cost of two-way splitting.
Apresentação
30/11/2011

Diffraction imaging point of common-offset gather: GPR data example
J. J. S. de Figueiredo, F. Oliveira, E. Esmi, L. Freitas, S. Green, A. Novais,
and J. Schleicher
SEG Expanded Abstracts 30, 4399-4403 (2011)

SUMMARY
Hydrocarbon traps are generally located beneath complex geological structures. Such areas contain many seismic diffractors that carry detailed structure information in the order of the seismic wavelength. Therefore, the development of computational resources capable of detecting diffractor points with a good resolution is desirable, but has been a challenge in the area of seismic processing. In this work, we present a method for the detection of diffractor points in the common-offset gathers domain. In our approach, the diffraction imaging is based on the diffraction operator, which can be used in both the
time and depth domains, in accordance with the complexity of the area. This method, which does not require any knowledge apart from the migration velocity field (i.e., rms velocities or interval velocities) applies pattern recognition to the amplitudes along the diffraction operator. Numerical examples using synthetic and real data demonstrate the feasibility of the technique.
Apresentação
29/11/2011

Coherence measures in automatic time migration velocity analysis
Jonathas S. Maciel, Jessé C. Costa (UFPA & INCT-GP, Brazil) and Jörg Schleicher (Unicamp & INCT-GP, Brazil)

SUMMARY
Time-migration velocity analysis can be carried out automatically by evaluating the coherence of the migrated seismic events in the common-image gathers (CIGs). The performance of gradient methods for automatic time-migration velocity analysis depends on the coherence measures used in the objective function. We compare the results of four different coherence measures, being conventional semblance, differential semblance, an extended differential semblance using more neighboring traces, and the product of the latter with conventional semblance. In our numerical experiments, the objective functions based on conventional semblance and on the product of conventional semblance with extended differential semblance provided the best velocity models, as evaluated by the flatness of the resulting common-image gathers. The method can be easily extended to anisotropic media.
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