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Poynting Vector Based Scalar Imaging Condition of Elastic Reverse Time Migration
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 80th EAGE Conference and Exhibition 2018, Jun 2018, Volume 2018, p.1 - 5
Abstract
We choose wavefield decoupling method to do wavefield separation in elastic reverse time migration. This decoupling method can maintain the phase and amplitude characteristics. However, the separated P- and S-wave both are vectors. We need to get scalar PP and PS image from these vectors. We use Poynting vector to scalarize vector P- and S-wave. However, the S-wave Poynting vector is inaccurate because S-wave stress has P-energy. So, we use S-wave quasi-stress to replace S-wave stress because S-wave quasi-stress is not affected by P-wave. We get a clear S-wave Poynting vector from S-wave quasi-stress. By these Poynting vectors, we use the dot product of P-wave Poynting vector and P-wave vector to get scalar P-wave. We introduce a reference S-wave and use the dot product of reference S-wave and vector S-wave to get scalar S-wave. Then we use acoustic-like imaging condition to get scalar PP and PS imaging results. With numerical tests, we can see that our imaging condition can hold imaging dynamic characteristics, not affected by propagation directions, no polarity reversal.