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 li...

P waves from regional-distance earthquakes are complex and reverberatory, as would be expected from a combination of head waves, post-critical crustal reflections and shallow-incident P waves from the upper mantle. Although designed for steeply-incident teleseismic P waves, receiver functions (RFs) can also retrieve information about crustal structure from regional P. Using a new computation me...

s). “Quantifying errors in fracture orientations estimated from PS converted wave” by Michelena (SEG 1995 Expanded Abstracts). “Stratigraphic inversion of poststack PS converted waves data,” by Valenciano and Michelena (SEG 2000 Expanded Abstracts). “Tomography + prestack depth migration of PS converted waves” by D’Agosto et al. (SEG 1998 Expanded Abstracts). “Pand S-wave separation ats). “Pand...

In this article we investigate AVO effects of large offset P-wave data (up to ) and converted waves (up to ). In addition to conventional P-wave AVO attributes ( and ) a third term ( ) is examined. For P to S converted waves we introduce two AVO attributes and . Background trends for certain cross plots are related to rock property relationships. These new attributes are used to discriminate co...

We apply 2-D wave-equation prestack depth migration to a North Sea basalt dataset. High velocity and impedance contrasts across a basalt layer causes low P-wave reflection signal-to-noise ratio under the basalt. We first migrate the P-wave data with a provided depth velocity model, and then replace sub-basalt P-wave velocity with a simple estimate of shear wave velocity and migrate locally-conv...