Automatic wave-equation migration velocity analysis by focusing subsurface virtual sources
نویسندگان
چکیده
منابع مشابه
Wave-equation Migration Velocity Analysis
In this report, we introduce a new wave-equation method of migration velocity analysis (MVA). The method is based on the linear relation that can be established between a perturbation in the migrated image and the generating perturbation in the slowness function. Our method consists of two steps: we first improve the focusing of the migrated image and then iteratively update the velocity model ...
متن کاملSubsurface Domain Image Warping by Horizontal Contraction and its Application to Wave-Equation Migration Velocity Analysis
A kinematically correct choice of velocity focuses subsurface offset image gathers at zero offset. Infinitesimal warping from the current image towards its focus can be approximated by a horizontal contraction. The image residual can be then taken as the difference between the warped and the original image to account for the velocity error. Least squares fitting of the effect of a velocity pert...
متن کاملWave - equation migration velocity analysis . I . Theory
We present a migration velocity analysis (MVA) method based on wavefield extrapolation. Similarly to conventional MVA, our method aims at iteratively improving the quality of the migrated image, as measured by the flatness of angle-domain commonimage gathers (ADCIGs) over the aperture-angle axis. However, instead of inverting the depth errors measured in ADCIGs using ray-based tomography, we in...
متن کاملWave-equation migration velocity analysis: Episode II
We elaborate the main points of the wave-equation migration velocity analysis method introduced in a previous report. We analyze its strengths and limitations, and illustrate them using a synthetic example. The inversion results confirm our original expectations, especially with regard to stability and robustness. The main difficulty in recovering a complete velocity perturbation is related to ...
متن کاملLinearized wave-equation migration velocity analysis by image warping
Seismic imaging produces images of contrasts in physical parameters in the subsurface, e.g., velocity or impedance. To build such images, a background model describing the wave kinematics in the earth is necessary. In practice, the structural image and background velocity model are unknown and have to be estimated from the acquired data. Migration velocity analysis deals with estimation of the ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: GEOPHYSICS
سال: 2018
ISSN: 0016-8033,1942-2156
DOI: 10.1190/geo2017-0213.1