3D Prestack Migration of Profiles
, by Yves Dezard
The 3D one-way wave operator downward continues a 2D seismic dataset in the 3D Cartesian coordinates. The 3D prestack migration gives a correct image of the earth's reflectivity interior since the time events are migrated to the correct location in the (x, y, z) space.
3D prestack migration in Cartesian coordinates is the depth downward continuation of both a 2D et of receiver profiles and a 2D set of source profiles in the frequency domain and the (S-G) coordinates.
The processing is mainly designed to correct the effects of severe depth and lateral velocity variations, wide angle offsets and steeply dipping beds. Most of the energy focuses at non-zero offset lines of the 2D shot profile dataset because the reflectors have significant dips.
Since we alternately downward continue the 2D sets of shot and geophone profiles, this energy focuses on a zero-offset line of another 2D set of shot profiles so there is no loss of energy on the edges.
STANFORD