| Summary: | Azimuthally-dependent P-wave AVO (amplitude variation with offset) responses can
be related to open fracture orientation and have been suggested as a geophysical tool
to identify fracture orientation in fractured oil and gas reservoirs. A field experiment
recently conducted over a fractured reservoir in the Barinas Basin (Venezuela) provides
data for an excellent test of this approach. Three lines of data were collected in
three different azimuths, and three component receivers were used. The distribution of
fractures in this reservoir was previously obtained using measurements of shear wave
splitting from P-S converted waves from the same dataset (Ata and Michelena, 1995).
In this work, we use P-wave data to see if the data can yield the same information using
azimuthal variation of P-wave AVO responses. Results obtained from the azimuthal
P-wave AVO analysis corroborate the results previously obtained using P-S converted
waves. This analysis with field data is an example of the high potential of P-waves to
detect fracture effects on seismic wave propagation.
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