When the relative simplicity of the subsurface does not warrant depth migration, pre-stack time migration (PreSTM) solutions will often suffice.
Our GX Technology (GXT) group has developed an amplitude-preserving Kirchhoff PreSTM routine that is ideal for imaging complex geologic conditions or velocity fields, yet without a requirement to employ pre-stack depth migration (PreSDM).
The GXT PreSTM methodology is not constrained by the straight ray approximation of most commercial PreSTM software packages. Instead, a turning ray approach is used that can image very steep or overturned seismic events. Capable of accounting for ray bending at angles up to 150o, GXT’s technique ensures there is no bias in the velocity estimates or in the positioning of steep dips.
The PreSTM algorithms used by GXT offer superior amplitude and bandwidth preservation. The results are better event coherency, improved lateral resolution, and gathers that are ideally suited as inputs into AVO analysis, especially in areas of complex geology.
