One important requirement for least-squares imaging (LSM) is having an accurate migration velocity model. LSM with large velocity errors results in erroneous reflector locations, strong swing artifact and even non-convergence. To mitigate these issues, we develop a novel least-squares imaging framework in the subsurface reflection angle domain. Instead of using high-wavenumber velocity perturbations for the reflectivity model as is done in traditional LSM, we parameterize the wave equation with an angle-dependent reflectivity, and derive the corresponding linearized forward modeling and adjoint migration operators. Because Gaussian Beam migration naturally incorporates the propagation directions in wavefield extrapolation, we represent the Green’s function using the Gaussian beam summation method. To improve the common-image gather (CIG) quality for low fold and low SNR data, a shaping regularization over the incident angle direction is introduced into the conjugate gradient scheme to iteratively update the angle-dependent reflectivity model. A flattening-enhanced summation is used to compute the stacked images by accounting for the depth moveout of CIGs caused by velocity errors, and produces constructive stacking results. Numerical experiments for a land survey demonstrate that the proposed method can improve LSM convergence and produce high-quality angle-dependent and stacked images with inaccurate migration velocity models.
Skip Nav Destination
SEG/AAPG/SEPM First International Meeting for Applied Geoscience & Energy
September 26–October 1, 2021
Denver, Colorado, USA and online
Angle-domain least-squares Gaussian beam migration
Jidong Yang;
Jidong Yang
China University of Petroleum (East China)
Search for other works by this author on:
Jianping Huang;
Jianping Huang
China University of Petroleum (East China)
Search for other works by this author on:
Zhenchun Li;
Zhenchun Li
China University of Petroleum (East China)
Search for other works by this author on:
George McMechan
George McMechan
The University of Texas at Dallas
Search for other works by this author on:
Paper presented at the SEG/AAPG/SEPM First International Meeting for Applied Geoscience & Energy, Denver, Colorado, USA and online, September 2021.
Paper Number:
SEG-2021-3567601
Published:
October 30 2021
Citation
Yang, Jidong, Huang, Jianping, Li, Zhenchun, Zhu, Hejun, and George McMechan. "Angle-domain least-squares Gaussian beam migration." Paper presented at the SEG/AAPG/SEPM First International Meeting for Applied Geoscience & Energy, Denver, Colorado, USA and online, September 2021. doi: https://doi.org/10.1190/segam2021-3567601.1
Download citation file:
Sign in
Don't already have an account? Register
Personal Account
You could not be signed in. Please check your username and password and try again.
Pay-Per-View Access
$9.00
Advertisement
9
Views
0
Citations
Advertisement
Suggested Reading
Advertisement