Elastic RTM: anisotropic wave‐mode separation and converted‐wave polarization correction

• DOI: 10.1190/1.3513505
• Publication Date: 2010-11-03T14:42:18Z
• Authors: Rongrong Lu; Jia Yan; Peter Traynin; John E. Anderson; Tom Dickens
• Keywords: Helmholtz free energy; Prestack

In this study, we investigate the impact of different wave‐mode separation approaches on TTI anisotropic elastic reverse time migration (RTM). We tested cheap but less accurate Helmholtz decomposition method as well expensive more pseudo‐derivative a simple 2D model. Our study shows that stacking operator associated with RTM algorithm can naturally remove most leaking‐mode artifacts generated by in media. Therefore, for purposes kinematic imaging, it is practically acceptable to use mode RTM. Another issue converted PS wavefields have mixed polarity depending P‐wave incidence angle. As result, given event has opposite signs shot images, causing be destroyed after over all shots. propose correction approach which angle‐domain common‐image gathers are computed at every imaging point and corrected angle domain before stacking. The polarization allows same stacked constructively yielding consistent image.