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P-And S-Wave Separated Elastic Reverse Time Migration for OBS Data from Fluid-Solid Media with Irregular Seabed Interfac
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 80th EAGE Conference and Exhibition 2018, Jun 2018, Volume 2018, p.1 - 5
Abstract
Elastic reverse time migration (ERTM) is being used for multi-component seismic data to obtain high quality images. However, the final images may suffer from artefacts caused by P- and S-wave crosstalk and some imaging noise caused by the rectangular grid discretization of the irregular seabed interfaces, when applying it on the OBS data from fluid-solid media with irregular seabed interfaces. To overcome the problem, we have developed a separated-wavefield ERTM in the curvilinear system. The first-order acoustic wave equations are transformed into that in the curvilinear system and applied into the fluid part. The P- and S-wave separated wave equation in the curvilinear system is derived and applied into the solid part. New vector imaging conditions are derived in the curvilinear system to obtain images in PP-x, PS-x, SP-x, SS-x, PP-z, PS-z, SP-z and SS-z components. Numerical examples on a layered fluid-solid model with irregular seabed interfaces suggest that the proposed ERTM can get more high quality images than three convention ERTM method with less imaging noise and artefacts.