Migration

The next step is to compare the subsurface-offset migration results from the two different data sets. Figure shows a comparison the two-way (a) vs. the one-way modeled data (b) migrations in the subsurface-offset domain. The results are comparable in terms of resolution, but the amplitudes show a different behavior. This is something to expect from the data differences in AVO behavior (Figure ). Even though the images shown in Figure are in the sub-surface offset domain, we can see how different they are going to be when transformed to reflection angle by using Sava and Fomel (2003) transformation.

 

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Figure 3 Comparison of the migration results in subsurface-offset domain of the two-way (a) vs. the one-way modeled data (b), and vs. the migration "Hessian impulse response" (c) (from equation 3)

Figure shows a comparison the two-way (Figure a) vs. the one-way modeled data (Figure b) migrations in the reflection angle domain. This result is obtained after applying an offset to angle transformation to the images in Figure . Notice the difference between the illumination patterns in the images. As we discussed in the modeling subsection the images in Figure a and Figure b should have different AVA responses. But, from inspecting the figures we can see that they are not that far apart. For most of the a x positions the angle range illumination is the same, being different in intensity. I will discuss the impact of this on the recovery of the AVA in the Inversion subsection.

 

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Figure 4 Comparison of the migration results in reflection angle of the two-way (a) vs. the one-way modeled data (b), and vs. the migration "Hessian impulse response" (c) (from equation 3)