Azimuthally-dependent P-wave AVO (amplitude variation with offset) responses canbe related to open fracture orientation and have been suggested as a geophysical toolto identify fracture orientation in fractured oil and gas reservoirs. A field experimentrecently conducted over a fractured reservoir in the Barinas Basin (Venezuela) providesdata for an excellent test of this approach. Three lines of data were collected inthree different azimuths, and three component receivers were used. The distribution offractures in this reservoir was previously obtained using measurements of shear wavesplitting 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 usingazimuthal variation of P-wave AVO responses. Results obtained from the azimuthalP-wave AVO analysis corroborate the results previously obtained using P-S convertedwaves. This analysis with field data is an example of the high potential of P-waves todetect fracture effects on seismic wave propagation.
展开▼
