3-D prestack depth migration is emerging as an industrial imaging tool. Many competing algorithms have been proposed by various authors. Nevertheless, the real bottleneck in 3D prestack processes is the sheer amount of input and output data. This paper reviews the principal migration methods on the basis of their capacity for data manipulation, without evaluating the algorithms themselves. It c...

Strong refraction of waves in the migration velocity model introduces kinematic artifacts coherent events not corresponding to actual reflectors into the image volumes produced by prestack depth migration applied to individual data bins. Because individual bins are migrated independently, the migration has no access to the bin component of slowness. This loss of slowness information permits eve...

The common-focus-point technology CFP describes prestack migration by focusing in two steps: emission and detection. The output of the first focusing step represents a CFP gather. This gather defines a shot record that represents the subsurface response resulting from a focused source wavefield. We propose applying the recursive shot-record, depthmigration algorithm to the CFP gathers of a seis...

Prestack migration algorithms are usually divided into two classes: ray-tracing based migration methods and wave-equation methods. The latter methods provide more accurate migration images, especially in complex geological areas, but they are the relatively expensive compared with ray-based migration methods. In this work, I test the phase encoding strategy on three types of one-way wave equati...

Prestack wave equation migration using the double square root equation produces prestack image volumes free of artifacts, even in the presence of multipathing due to complex structure. In particular image gathers in angle or offset ray parameter are flat at correct velocity, and gathers in offset are concentrated at zero offset. Differential semblance measures the deviation from flatness or con...

Two hundred km of 2D seismic survey was carried out at the Lesser Himalayan Thrust Belts in Dailekh district, western Nepal. The main motivation is to elucidate geologic relationship between known oil and gas seeps, subsurface structure, stratigraphy area. This a challenging task which from its extreme structural geological complexity such as thrust faulting, tight folding, steep dip layers, st...

Shot-geophone migration, commonly accomplished using wavefield depth extrapolation (“survey sinking”), has a two way reverse time realization as well. The reverse time version permits imaging of overturned reflections. Shot-geophone migration differs from other prestack migrations in the definition of the prestack image volume which it creates. This difference is most clearly seen by identifyin...

Seismic image and velocity models were obtained from a newly conducted seismic survey around the Integrated Ocean Drilling Program (IODP) Japan Trench Fast Drilling Project (JFAST) drill site in the Japan Trench. Pre-stack depth migration (PSDM) analysis was applied to the multichannel seismic reflection data to produce an accurate depth seismic profile together with a P wave velocity model alo...

Constructing the seismic image in vertical time, as opposed to depth, eliminates the inherent ambiguity of resolving the vertical P -wave velocity from surface seismic data in transversely isotropic media with a vertical axis of symmetry (VTI media). By ray tracing in the space-time (x-τ)-domain, a traveltime map is built by interpolating the traveltime information along the rays onto a regular...