One-step Least-square Reverse Time Migration Using Wavefield Decomposition Imaging Condition
H. Xue, Y. Liu, J. Wang and H. Zhou
Event name: 80th EAGE Conference and Exhibition 2018
Session: Poster: Seismic Imaging - Least Squares and Migration
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 530.33Kb )
Price: € 20
In this study, we implement least-square reverse time migration (LSRTM) using one-step extrapolated exponential matrix method and wavefield decomposition imaging condition. One-step extrapolated exponential matrix method employs the Chebyshev polynomial expansion to approximate the exponential of the matrix and it propagates waves free of numerical dispersion noise. Using an analytical wavefield generated by one-step extrapolated exponential matrix method, we can separate the wavefield into upgoing and downgoing both in source and receiver wavefield in an explicit way, which can improve the efficiency the iterative LSRTM algorithm. The wavefield decomposition imaging condition is used in the calculation of gradient in the LSRTM to suppress the low-frequency artifacts. Synthetic examples demonstrate that this method is effective and it can successfully suppress the low-frequency artifacts.