We present 3D prestack map time migration in closed form for qP-, qSV-, and mode-converted waves in homogeneous transversely isotropic media with a vertical symmetry axis (VTI). As far as prestack time demigration is concerned, we present closed-form expressions for mapping in homogeneous isotropic media, while for homogeneous VTI media we present a system of four nonlinear equations with four ...

A key to reducing the risks and costs of associated with oil and gas exploration is the fast, accurate imaging of complex geologies, such as salt domes in the Gulf of Mexico and overthrust regions in U.S. onshore regions. Prestack depth migration generally yields the most accurate images, and one approach to this is to solve the scalar wave equation using nite diierences. Current industry compu...

In areas with structurally complex geology, tomographic velocity analysis is required to estimate velocities. This paper describes a tomographic velocity analysis algorithm which uses planewave synthesis imaging as a prestack migration. In reflection tomography, prestack migration is required for both event picking and traveltime error computation. Traveltime errors are often measured in the fo...

Recent analysis and synthetic examples have shown that many prestack depth migration methods produce non-flat image gathers containing spurious events, even when provided with a kinematically correct migration velocity field, if this velocity field is highly refractive. This pathology occurs in all migration methods which produce partial images as independent migrations of data bins. Shot-geoph...

3-D shot-gather prestack depth migration based on wave equation is an important method because of its good capability of imaging complex subsurface structures. In this paper, 3-D parallel shot-gather prestack depth migration with hybrid is developed and implemented. The shot-gather migration has high natural parallel feature because different processor can process shot-gather independently. Suc...

Complex seismic signatures are generated due to the complexity of the subsurface which is difficult to interpret. In the present study, an attempt has been made to model the complex subsurface using the Ray tracing modeling technique. Add to this, for the imaging of these geological features, Kirchhoff’s prestack depth migration is applied over the synthetic common shot gather dataset. It is fo...

Migration velocity analysis includes both depth-focusing analysis and residual curvature analysis of coherency panels. In either method, it is widely used for 2-D velocity analysis in regions of complex geological structures. Unfortunately, since complex structures tend to be 3-D structures, 3-D prestack depth migration is desirable. The most commonly proposed candidate is kinematic Kirchhoff m...

in exploration seismology, migration refers to a multi-channel processing step that attempts to spatially re-position events and improve focusing. before migration, seismic data is usually displayed with traces plotted at the surface location of the receivers and with a vertical time axis. this means that dipping reflections are systematically mispositioned in the lateral coordinate and the ver...