Symplectic scheme and the Poynting vector in reverse-time migration

Geophysics ◽  
2014 ◽  
Vol 79 (5) ◽  
pp. S163-S172 ◽  
Author(s):  
Edvaldo S. Araujo ◽  
Reynam C. Pestana ◽  
Adriano W. G. dos Santos
Keyword(s):  
Poynting Vector ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration ◽  
Symplectic Scheme

Symplectic scheme and the Poynting vector in the reverse time migration

2013 ◽  
Author(s):  
Edvaldo S. Araujo ◽  
Reynam C. Pestana ◽  
Adriano W. G. dos Santos
Keyword(s):  
Poynting Vector ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration ◽  
Symplectic Scheme

Symplectic scheme and the Poynting vector in the reverse time migration

2013 ◽  
Author(s):  
Edvaldo S. Araujo ◽  
Reynam C. Pestana ◽  
Adriano W. G. dos Santos
Keyword(s):  
Poynting Vector ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration ◽  
Symplectic Scheme

Combining multidirectional source vector with antitruncation-artifact Fourier transform to calculate angle gathers from reverse time migration in two steps

Geophysics ◽  
2017 ◽  
Vol 82 (5) ◽  
pp. S359-S376 ◽  
Author(s):  
Chen Tang ◽  
George A. McMechan
Keyword(s):  
Fourier Transform ◽  
Plane Wave ◽  
Poynting Vector ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Step ◽  
Imaging Condition ◽  
Time Migration ◽  
Reflection Image ◽  
Wave Decomposition

Because receiver wavefields reconstructed from observed data are not as stable as synthetic source wavefields, the source-propagation vector and the reflector normal have often been used to calculate angle-domain common-image gathers (ADCIGs) from reverse time migration. However, the existing data flows have three main limitations: (1) Calculating the propagation direction only at the wavefields with maximum amplitudes ignores multiarrivals; using the crosscorrelation imaging condition at each time step can include the multiarrivals but will result in backscattering artifacts. (2) Neither amplitude picking nor Poynting-vector calculations are accurate for overlapping wavefields. (3) Calculating the reflector normal in space is not accurate for a structurally complicated reflection image, and calculating it in the wavenumber ([Formula: see text]) domain may give Fourier truncation artifacts. We address these three limitations in an improved data flow with two steps: During imaging, we use a multidirectional Poynting vector (MPV) to calculate the propagation vectors of the source wavefield at each time step and output intermediate source-angle-domain CIGs (SACIGs). After imaging, we use an antitruncation-artifact Fourier transform (ATFT) to convert SACIGs to ADCIGs in the [Formula: see text]-domain. To achieve the new flow, another three innovative aspects are included. In the first step, we develop an angle-tapering scheme to remove the Fourier truncation artifacts during the wave decomposition (of MPV) while preserving the amplitudes, and we use a wavefield decomposition plus angle-filter imaging condition to remove the backscattering artifacts in the SACIGs. In the second step, we compare two algorithms to remove the Fourier truncation artifacts that are caused by the plane-wave assumption. One uses an antileakage FT (ALFT) in local windows; the other uses an antitruncation-artifact FT, which relaxes the plane-wave assumption and thus can be done for the global space. The second algorithm is preferred. Numerical tests indicate that this new flow (source-side MPV plus ATFT) gives high-quality ADCIGs.

Obliquity-correction imaging condition for reverse time migration

Geophysics ◽  
2009 ◽  
Vol 74 (3) ◽  
pp. S57-S66 ◽  
Author(s):  
J. C. Costa ◽  
F. A. Silva Neto ◽  
M. R. Alcântara ◽  
J. Schleicher ◽  
A. Novais
Keyword(s):  
Poynting Vector ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Illumination Compensation ◽  
Imaging Condition ◽  
Time Migration ◽  
Imaging Point ◽  
Stationary Phase Analysis ◽  
Seismic Images

The quality of seismic images obtained by reverse time migration (RTM) strongly depends on the imaging condition. We propose a new imaging condition that is motivated by stationary phase analysis of the classical crosscorrelation imaging condition. Its implementation requires the Poynting vector of the source and receiver wavefields at the imaging point. An obliquity correction is added to compensate for the reflector dip effect on amplitudes of RTM. Numerical experiments show that using an imaging condition with obliquity compensation improves reverse time migration by reducing backscattering artifacts and improving illumination compensation.

Reverse-Time Migration using the Poynting Vector

2006 ◽  
Vol 37 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Kwangjin Yoon ◽  
Kurt J. Marfurt
Keyword(s):  
Poynting Vector ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Time Migration
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