Detection of fracture orientation using azimuthal variation of P-wave AVO responses

Azimuthally dependent P-wave amplitude variation with offset (AVO) response s can be related theoretically to open fracture orientation and have been s uggested as a geophysical tool to identify fracture orientation in fracture d oil and gas reservoirs. A field experiment conducted recently over a frac tured reservoir in the Barinas Basin, Venezuela provides data for an excell ent test of this approach. Three lines of data were collected in three diff erent azimuths, and three component receivers were used. The distribution o f fractures in this reservoir was obtained previously using measurements of shear-wave splitting from P-S converted waves from the same data set. In t his work, we use P-wave data to see if the data can yield the same informat ion using azimuthal variation of P-wave AVO responses. Results obtained fro m the azimuthal P-wave AVO analysis corroborate the fracture orientation ob tained previously using P-S converted waves. This analysis with field data is an example of the high potential of P-waves to detect fracture effects o n seismic wave propagation.