Plane-wave Least-squares Reverse Time Migration in Anisotropic Media Using Low-rank Finite Difference
J.Q. Huang, C. Li and Z.C. Li
Event name: 79th EAGE Conference and Exhibition 2017
Session: Seismic Anisotropy in Fractured Reservoirs - The Anisotropic Signatures
Publication date: 12 June 2017
Info: Extended abstract, PDF ( 1.69Mb )
Price: € 20
Least-squares reverse time migration (LSRTM) based on anisotropic propagator is a powerful tool for imaging the complicated geologic structure in the subsurface. But conventional demigration operator was applied in anisotropic LSRTM was built by using pseudo-acoustic wave equation, which may suffer from physical instability and undesirable noise. To overcome these defects, firstly, low-rank finite-difference method was employed to establish the linearized modeling operator for relieving wavefield instability and suppressing unwanted noise caused by qSV-wave artifacts, and then the forward modeling operator and its adjoint were used to implement LSRTM, in addition, plane-wave encoding strategy was introduced to the inversion framework of anisotropic media for decreasing the I/O and storage demands and improving the inversion efficiency. Numerical tests on synthetic dataset with a complex Marmousi model demonstrate wave-extrapolation operator based on low-rank finite-difference can produce stable wavefield, and good images can be generated by the proposed method.