No abstract

The frequency‐domain approach to migration extends to three dimensions. Application of the ray‐tracing approach to simple seismic events, together with the principle of superposition for complex events, leads to the correct equation for frequency‐domain migration in a constant velocity medium and a further understanding of the basic migration procedure in three dimensions. In the frequency domain, three‐dimensional (3-D) migration may be reduced to a series of two‐dimensional (2-D) migrations. A 3-D seismic model can be generated economically for structures with combinations of radial and 2-D symmetry. Starting from a 2-D synthetic, a 3-D model can be constructed by rotation about the axis of symmetry. Any line across the model may then be synthesized from the basic 2-D data. Certain more complex 3-D models can also be developed using the superposition of simpler models. Synthetic examples are used to illustrate the fact that 2-D migration of 3-D seismic data will not generally result in a correct section.

No abstract

The frequency domain approach to migration extends to three dimensions. The application of a ray tracing approach to simple seismic events and the principle of superposition leads to the correct equation for the frequency domain migration and a further understanding of the basic migration procedure in three dimensions., Synthetic examples are used to illustrate the fact that two-dimensional migration of three-dimensional data will not result in a correct section. However, in the frequency domain, three-dimensional migration may be reduced to a series of two-dimensional migrations.The synthetics for this paper were generated by a particularly fast and straightforward technique. Such a fast three-dimensional seismic model can be generated for structures with certain symmetry. Starting from a two-dimensional synthetic, a threedimensional model can be constructed by rotation about the center of symmetry. Any line across the feature may then be synthesized from the basic data.Certain more complex three-dimensional models can also be developed using the superposition of simpler models.