Interferometric correlogram-space analysis
Seismic interferometry is a method of obtaining a virtual shot gather from a collection of actual shot gathers. The set of traces corresponding to multiple actual shots recorded at two receivers is used to synthesize a virtual shot located at one of the receivers and a virtual receiver at the ot...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Technical Report |
| Published: |
Massachusetts Institute of Technology. Earth Resources Laboratory
2012
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| Subjects: | |
| Online Access: | http://hdl.handle.net/1721.1/68345 |
| Summary: | Seismic interferometry is a method of obtaining a virtual shot
gather from a collection of actual shot gathers. The set of traces
corresponding to multiple actual shots recorded at two receivers is
used to synthesize a virtual shot located at one of the receivers and
a virtual receiver at the other. An estimate of a Green’s function between
these two receivers is obtained by first cross-correlating pairs
of traces from each of the common shots and then stacking the resulting
cross-correlograms. In this paper, we study the structure of
cross-correlograms obtained from a VSP acquisition geometry using a
surface source reflected by flat or dipping layers and/or diffracted by
point inclusions. The model is purely acoustic. The shape of events
in the cross-correlogram space can be used to infer the location and
geometry of a subsurface structure. A pilot wavelet created by a curvilinear
stacking process is used as a detector of predicted events in the
cross-correlogram. Results of a semblance-based velocity scan of the
cross-correlograms using curvilinear stacks can be used to improve the
quality of the virtual gather. |
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