Optimal Imaging Aperture for computational efficiency in 2D and 3D Reverse Time Migration using SeisRTM

Seismic migration is essential for converting seismic data into accurate subsurface images. The computational cost of migration is influenced by the migration algorithm, data dimensionality, and geological medium properties. Among the various methods, Reverse Time Migration (RTM) based on the two-way wave equation is regarded as the most precise for handling complex subsurface conditions. However, the complexity and computational demands of RTM increase significantly with transitions from isotropic to anisotropic media and from 2D to 3D data. Additionally, the choice of imaging aperture strongly affects RTM’s computational cost, making an optimal aperture crucial for accurately imaging subsurface features while managing resources. In this study, we investigate 2D TTI and 3D isotropic RTM, focusing on the impact of shot-centric and fold-centric aperture selection on computational efficiency and imaging accuracy using the in-house developed SeisRTM software suite. Experiments on synthetic and real field data show that the fold-centric aperture reduces memory and compute time by up to 1.4x compared to the shot-centric aperture while maintaining comparable image quality. These findings highlight fold-centric apertures as a computationally efficient choice for large-scale seismic imaging, especially in resource-intensive environments. SeisRTM’s capabilities in high-frequency migration, large dataset handling, and target-oriented migration were instrumental in this study, highlighting it as an efficient tool for large-scale RTM applications.