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Attenuation Anisotropy in TI Media - Inversion for Fracture Dip
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
The existence of aligned fractures leads to attenuation anisotropy as well as velocity anisotropy. Our research focuses on attenuation due to wave induced fluid flow in fractured porous media, and aims to predict fracture dip with anisotropic attenuation information extracted from surface and downhole seismic data. As the linear slip viscoelastic model predicts, both P- and SV-wave attenuation coefficients reach the minimum values when the ray path direction is parallel to the fracture planes. To successfully predict the fracture dip, we use modified spectra ratio method to estimate attenuation from seismic data, and then extract fracture dip from anisotropic attenuation data. We use two trigonometric functions to fit P- and SV-wave anisotropic attenuation data. The inversion problem can be described as determining a dip angle which results in minimum P- and SV-wave attenuation based on the fitted trigonometric curves. This method proves to be feasible through our test on synthetic viscoelastic wave field data of VTI medium.