Migration and velocity analysis by velocity continuation
نویسنده
چکیده
Residual and cascaded migration can be described as a continuous process of velocity continuation in the post-migration domain. This process moves reflection events on the migrated seismic sections according to changes in the migration velocity. Understanding the laws of velocity continuation is crucially important for a successful application of migration velocity analysis. In this paper, I derive the kinematic laws for the case of prestack residual migration from simple trigonometric principles. The kinematic laws lead to dynamic theory via the method of characteristics. The main theoretical result is a decomposition of prestack velocity continuation into three different components corresponding to residual normal moveout, residual dip moveout, and residual zero-offset migration. The contribution and properties of each of the three components are analyzed separately.
منابع مشابه
Time-migration velocity analysis by velocity continuation
Time-migration velocity analysis can be performed by velocity continuation, an incremental process that transforms migrated seismic sections according to changes in the migration velocity. Velocity continuation enhances residual normal moveout correction by properly taking into account both vertical and lateral movements of events on seismic images. Finite-difference and spectral algorithms pro...
متن کاملVelocity continuation in migration velocity analysis
Velocity continuation can be applied to migration velocity analysis. It enhances residual NMO correction by properly taking into account both vertical and lateral movements of reflectors caused by the change in migration velocity. I exemplify this fact with simple data tests.
متن کاملNumerical Velocity Continuation in the Post - Stack Domain
Time migration velocity analysis can be performed by velocity continuation, an incremental process that transforms migrated seismic sections according to changes in the migration velocity. Velocity continuation enhances residual normal moveout correction by properly taking into account both vertical and lateral movements of events on seismic images. Finite-difference and spectral algorithms pro...
متن کاملVelocity continuation and the anatomy of residual prestack time migration
Velocity continuation is an imaginary continuous process of seismic image transformation in the postmigration domain. It generalizes the concepts of residual and cascaded migrations. Understanding the laws of velocity continuation is crucially important for a successful application of time-migration velocity analysis. These laws predict the changes in the geometry and intensity of reflection ev...
متن کاملAngle-domain common-image gathers for migration velocity analysis by wavefield-continuation imaging
We analyze the kinematic properties of offset-domain Common Image Gathers (CIGs) and Angle-Domain CIGs (ADCIGs) computed by wavefield-continuation migration. Our results are valid regardless of whether the CIGs were obtained by using the correct migration velocity. They thus can be used as a theoretical basis for developing Migration Velocity Analysis (MVA) methods that exploit the velocity inf...
متن کامل