Imaging in depth

From SEG Wiki
Jump to navigation Jump to search
ADVERTISEMENT
Seismic Data Analysis
Seismic-data-analysis.jpg
Series Investigations in Geophysics
Author Öz Yilmaz
DOI http://dx.doi.org/10.1190/1.9781560801580
ISBN ISBN 978-1-56080-094-1
Store SEG Online Store


Following the tomographic updating described above, perform 3-D prestack depth migration using the final velocity-depth model (Figure 10.8-12) to generate the image sections along the selected inline traverses. Shown in Figure 10.8-16 are selected image gathers along the three inline traverses. Stack of the image gathers yields the final image from 3-D prestack depth migration. Shown in Figure 10.8-17 are three inline sections from the image volume and in Figure 10.8-18 are the same inline sections with reverse polarity for better identification of some of the fault planes. Compare these image sections with those derived from 3-D prestack depth migration before the tomographic update shown in Figures 10.8-8 and 10.8-9, and note that the tomographic update of the model has improved the image quality within the zone with intensive faulting.

Once the image quality from the selected inlines is judged to be acceptable, perform 3-D prestack depth migration to produce the entire image volume. Shown in Figure 10.8-19 are selected inline sections from the image volume derived from 3-D prestack depth migration using the final velocity-depth model. While the selected inline sections from 3-D prestack depth migration as in Figure 10.8-18 were created using the Kirchhoff summation algorithm, the entire image volume represented by the inline sections in Figure 10.8-19 was created using the common-offset 3-D phase-shift-plus-correction algorithm (3-D prestack depth migration). This choice for creating the image volume was primarily for faster turnaround. Selected crossline sections from the image volume in depth are shown in Figure 10.8-20. Note from the inline and crossline sections in Figures 10.8-19 and 10.8-20 the intensive faulting and folding caused by the wrench tectonism.

  • Figure 10.8-8  Stack of the image gathers as in Figure 10.8-7 along three inlines (from top to bottom: Inlines 105, 155, and 205 with 1250-m distance between them).

    Figure 10.8-8  Stack of the image gathers as in Figure 10.8-7 along three inlines (from top to bottom: Inlines 105, 155, and 205 with 1250-m distance between them).

  • Figure 10.8-12  Maps of layer velocities (left column) and reflector geometries (right column) associated with the data as in Figure 10.8-3 after tomographic update. Compare with the maps in Figure 10.8-6 before the update.

    Figure 10.8-12  Maps of layer velocities (left column) and reflector geometries (right column) associated with the data as in Figure 10.8-3 after tomographic update. Compare with the maps in Figure 10.8-6 before the update.

  • Figure 10.8-16  Selected image gathers from 3-D prestack depth migration of the data as in Figure 10.8-3 using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12. Compare with the image gathers in Figure 10.8-7 before the tomographic update.

    Figure 10.8-16  Selected image gathers from 3-D prestack depth migration of the data as in Figure 10.8-3 using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12. Compare with the image gathers in Figure 10.8-7 before the tomographic update.

  • Figure 10.8-17  Stack of the image gathers as in Figure 10.8-16 along three inlines (from top to bottom: Inlines 105, 155, and 205 with 1250-m distance between them). Compare with the image sections in Figure 10.8-8 before the tomographic update.

    Figure 10.8-17  Stack of the image gathers as in Figure 10.8-16 along three inlines (from top to bottom: Inlines 105, 155, and 205 with 1250-m distance between them). Compare with the image sections in Figure 10.8-8 before the tomographic update.

  • Figure 10.8-18  The same three inline sections as in Figure 10.8-17 with reverse polarity. Compare with the image sections in Figure 10.8-9 before the tomographic update.

    Figure 10.8-18  The same three inline sections as in Figure 10.8-17 with reverse polarity. Compare with the image sections in Figure 10.8-9 before the tomographic update.

  • Figure 10.8-19  Part 1: Selected inline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

    Figure 10.8-19  Part 1: Selected inline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

  • Figure 10.8-19  Part 2: Selected inline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

    Figure 10.8-19  Part 2: Selected inline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

  • Figure 10.8-19  Part 3: Selected inline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

    Figure 10.8-19  Part 3: Selected inline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

  • Figure 10.8-20  Part 1: Selected crossline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

    Figure 10.8-20  Part 1: Selected crossline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

  • Figure 10.8-20  Part 2: Selected crossline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

    Figure 10.8-20  Part 2: Selected crossline sections from the image volume derived from 3-D prestack depth migration using the updated velocity-depth model based on the layer velocities and reflector geometries shown in Figure 10.8-12.

See also

External links

find literature about
Imaging in depth 		SEG button search.png Datapages button.png GeoScienceWorld button.png OnePetro button.png Schlumberger button.png Google button.png AGI button.png
Retrieved from "https://wiki.seg.org/w/index.php?title=Imaging_in_depth&oldid=19644"