Full text loading...
-
Frequency-dependent AVO Response in Porous Rocks with Aligned Fractures
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
Presence of planar fractures in a fluid-saturated porous rock causes significant anisotropic attenuation and dispersion of seismic waves mainly due to wave-induced fluid flow (mesoscopic loss) between porous and fractures. The most recent studies are focused on anisotropic attenuation and velocity dispersion. However, research about reflection response at an interface between a non-dispersive medium and fluid-saturated porous rocks with aligned fractures is poor. In this paper, we have investigated the characteristics of reflection amplitude variations as a function of frequency and incident-angle and studied on how formation parameters impact on its dispersive and anisotropic feature. The results show that PP-wave reflection varies with frequency in low frequency and small incident angle strongly than in high frequency and large incident angle. Besides that the dispersion strength and anisotropy of PP-wave reflection strongly influenced by porosity, fracture spatial period, normal fracture weakness and it is independent with shear fracture weakness. These results could provide insight for frequency-dependent AVO analysis and inversion.