| Autor: |
Parra, Jorge O., Sturdivant, Vernon R., Xu, Pei-cheng |
| Zdroj: |
Journal of the Acoustical Society of America; 1993, Vol. 93 Issue 4, p1954-1969, 16p |
| Abstrakt: |
A dipping fractured layer zone has a characteristic seismic signature in interwell seismic data. A fracture zone is simulated as a dipping low-velocity layer in an unbounded medium using the elastodynamic Green's function for layered earth to include absorption and dispersion effects. The vector wave displacement solution is developed for a point force at an arbitrary angle with respect to the axis of symmetry of a horizontal layer. The source and detector boreholes are rotated such that the new boreholes are perpendicular to the force to form a new plane which contains a dipping layer and horizontal force. To simulate interwell seismic responses, a modified Clenshaw-Curtis quadrature method for wave-number integrals of the Bessel function type is developed to evaluate the wave displacement vector in the frequency-space domain. The model results demonstrate that the presence of a dipping low-velocity layer produces seismic signatures associated with the attitude of the low-velocity layer and the angle of the layer with respect to the source. Also, the results suggest that the amplitudes of shear wave events associated with the presence of a dipping low-velocity layer diminish and their hyperbolic moveout patterns are modified as the dipping layer becomes horizontal. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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