Seismic images reconstructed by migration from seismic data recorded at the surface represent the earth structure at every location in the subsurface. The data are remapped into the subsurface by using a wave equation and an estimate of the earth velocity. The velocity model is of great importance for obtaining accurate seismic images and for understanding the subsurface reservoir properties an...

We have ported serial codes for 2-D and 3-D seismic depth migration to parallel platforms. The porting was done using portable parallel primitives, such that the same code can be run on a . number of parallel machines, workstation clusters, as well as serial machines. Only small modifications of the serial codes were necessary. Efficient parallel codes were obtained with moderate modification o...

An anti-aliasing formula is derived for interferometric redatuming of seismic data. More generally, this formula is valid for numerical implementation of the reciprocity equations of correlation type, which is used for redatuming, extrapolation, interpolation, and migration. The anti-aliasing condition can be, surprisingly, more tolerant of a coarser trace sampling compared to the standard anti...

Seismic images obtained by multicomponent wave-equation migration can be decomposed into angle-gathers with a transformation that generalizes the equivalent construction for primary waves. A particularly simple formulation is to use all three components of the offset vector separating sources and receivers at image points. Using full vector offsets, multicomponent angle-gathers are built using ...

the radial trace transform was introduced by the stanford exploration project many years ago (ottolini, 1979 and claerbout, 1983), primarily for use in migration and imaging applications. it has been shown subsequently, because of its particular geometry, to be very useful for wavefield separation (claerbout, 1983) and coherent noise attenuation (henley, 1999). the radial trace transform, unlik...

What migration sets-out to do Deriving parameters for migration: 1D versus 3D assumptions Inversion Estimating image uncertainty Resolution scale length Generic model building loop for ray-based tomography Parametric versus non-parametric autopicking Wide azimuth and multi-azimuth data Anisotropic Model Building Anisotropic pre-stack depth migration in the absence of well control Resolving near...

We present the theory and numerical results for least-squares migration of traces generated by simultaneous sources. Numerical tests show that standard seismic data processing, such as stacking and migration, can effectively suppress some crosstalk associated with simultaneous sources data, and so can separate shot gathers from one another. In contrast, LSM can remove most of the noise from sim...

Many commonly used shallow seismic sources are unacceptable for hazardous waste site investigations because they risk exhumation of contaminants in the soil, they add contaminants (e.g. lead) which are not allowed by regulations, or they add new migration paths for contaminants. Furthermore, recently developed high frequency vibrators for shallow investigations could be more effective at some s...

We extend time-domain velocity continuation to the zero-offset 3D azimuthally anisotropic case. Velocity continuation describes how a seismic image changes given a change in migration velocity. This description turns out to be of a wave propagation process, in which images change along a velocity axis. In the anisotropic case, the velocity model is multi-parameter. Therefore, anisotropic image ...