Conclusions/Future Considerations

It is clear that the migration algorithm described and implemented in this paper does a good job of imaging in the presence of complex geology. The result from the prestack migration vs. the poststack migration shows that in this case, the use of the prestack migration algorithm was not only beneficial, it was necessary. However, the limitations of the use of this procedure by itself are shown in its failure to image certain parts of the model. Though simple tweaking of the velocity model can prove to help image different parts, others were not visible. The faulted blocks with the relatively high S-wave impedance contrasts are symbolic of a real life possibility where the layers are brine-bearing sediments. In this case, these layers are important things to image, so that they are avoided while drilling. To image these parts,we would need some special processing to take place. One method that could be used is multiple attenuation. If the multiples from the water bottom and salt were adequately attenuated, the gain could be turned up and the low amplitude signals might be more easily seen. Another method is to mute the energy in the data so that only the target reflections (deeper units of interest) would be imaged.

Currently, we are considering the latter, and there is initial evidence that the S-wave energy from the left fault block layers is enough that it can be identified and separated from the rest of the energy on the CMP gathers. If this can be done for all the CMPs which correspond to that part of the image, there is a good possibility that we could image these blocks.