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...

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...

Common-reflection-point (CRP) gathers provide important clues in various migration velocity analysis schemes (Al-Yahya, 1987; Etgen, 1990). Conventionally, CRP gathers are obtained by prestack migration of shot records or constant-offset sections. This paper introduces a way to generate a CRP gather for residual velocity analysis using wavefront synthesis imaging. Compared to CRP gathers obtain...

Wave-equation migration is an accurate and robust alternative to Kirchhoff migration when multipathing and other complex wave phenomena occur, such as in subsalt exploration. In these situations, images obtained by wave-equation migration are often superior to images obtained by Kirchhoff methods. However, 3-D wave-equation prestack imaging is an immature technology compared with Kirchhoff imag...

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 de...

I present a general methodology for computing Angle-Domain Common Image Gathers (ADCIGs) in conjunction with anisotropic wavefield-continuation migration. The method is based on the transformation of the prestack image from the subsurface-offset domain to the angle domain by use of slant stacks. The processing sequence is the same as for the computation of ADCIGs for the isotropic case, though ...

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...

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...