A wavefield-separation-based elastic least-squares reverse time migration

• DOI: 10.1190/geo2017-0131.1
• Publication Date: 2018-02-09T08:27:38Z
• Authors: Bingluo Gu; Zhenchun Li; Jianguang Han
• Keywords: Seismic migration; Least-squares function approximation; Crosstalk; Wave vector

Elastic least-squares reverse time migration (ELSRTM) has the potential to provide improved subsurface reflectivity estimation. Compared with elastic RTM (ERTM), ELSRTM can produce images higher spatial resolution, more balanced amplitudes, and fewer artifacts. However, crosstalk between P- S-waves significantly degrade imaging quality of ELSRTM. We have developed an method suppress This includes three crucial points. The first is that forward backward wavefields are extrapolated based on separated velocity-stress equation S-waves. second vector S-wave residuals migrated form Lamé constants [Formula: see text] independently. third obtained by P-wave achieved in extrapolation residuals, respectively. Numerical tests synthetic data demonstrate our free coupled wavefields, better convergence accuracy.