Parallelisation of a code for seismic depth migration

Author(s):  
A. Buland ◽  
R. Sollie ◽  
J. Amundsen
2014 ◽  
Vol 577 ◽  
pp. 1211-1214
Author(s):  
Shan Hui Xu ◽  
Jian Guo ◽  
Pei Pei Li

This paper presents a method for multi-point vibration location near-surface. Unlike traditional source location technologies, it is not using travel times of seismic waves for positioning calculation, but according to the entire seismic data record, using the wave equation migration method to calculate the source location. Similar to exploration seismic, the records from a survey line within a certain period of time are data volumes with dimensions of time and ground coordinates. Based on the data, combined with surface seismic wave propagation characteristics, by using the improved seismic depth migration algorithm, the vibration energy will return to the starting position where exactly the source location is. The method can solve the problem of location calculation error by using traditional method when several vibration at the same time or continuous vibration occurs at some point.


Geophysics ◽  
2006 ◽  
Vol 71 (3) ◽  
pp. S111-S120 ◽  
Author(s):  
Gary F. Margrave ◽  
Hugh D. Geiger ◽  
Saleh M. Al-Saleh ◽  
Michael P. Lamoureux

We present a new approach to the design and implementation of explicit wavefield extrapolation for seismic depth migration in the space-frequency domain. Instability of the wavefield extrapolation operator is addressed by splitting the operator into two parts, one to control phase accuracy and a second to improve stability. The first partial operator is simply a windowed version of the exact operator for a half step. The second partial operator is designed, using the Wiener filter method, as a band-limited, least-squares inverse of the first. The final wavefield extrapolation operator for a full step is formed as a convolution of the first partial operator with the complex conjugate of the second. This resulting wavefield extrapolation operator can be designed to have any desired length and is generally more stable and more accurate than a simple windowed operator of similar length. Additional stability is gained by reducing the amount of evanescent filtering and by spatially downsampling the lower temporal frequencies. The amount of evanescent filtering is controlled by building two operator tables, one corresponding to significant evanescent filtering and the other to very little evanescent filtering. During the wavefield extrapolation process, most steps are taken with the second table while the first is invoked only for roughly every tenth step. Also, the data are divided into frequency partitions that are optimally resampled in the spatial coordinates to further enhance the performance of the extrapolation operator. Lower frequencies are downsampled to a larger spatial sample size. Testing of the algorithm shows accurate, high-angle impulse responses and run times comparable to the phase shift method of time migration. Images from trial depth migrations of the Marmousi model show very high resolution.


2009 ◽  
Author(s):  
Abhijit Gangopadhyay ◽  
Robert Lauck ◽  
Fabian Wirnkar ◽  
T. Chris Stiteler ◽  
Ron Berryman ◽  
...  

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