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Gassmann-consistent Born Inversion for Fracture Density
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 78th EAGE Conference and Exhibition 2016, May 2016, Volume 2016, p.1 - 5
Abstract
We present new method for elastic waveform inversion in anisotropic media which is based on a combination of the well-known (single scattering) Born approximation with a Gassmann-consistent rock physics model for the overall properties of materials with interconnected pores and fractures. Previous attempts to perform a Born inversion for fracture parameters have been based on an model of isolated fractures. However, the predictions of the isolated fracture model can be very different from those of a Gassmann-consistent model of interconnected pores and fractures, due to the phenomenon of dispersion. We have performed a series of numerical experiments to investigate the effects of pore fluid pressure communication on the results of a Born inversion for fracture density. Our numerical experiments are associated with a HTI model of interconnected pores and vertically aligned fractures, but our rock physics based approach to elastic waveform inversion can in principle also be used for anisotropic systems of lower symmetry. The results of our numerical experiments suggest that it is essential to use a Gassmann-consistent rock physics model that accounts for hydraulic connection between the pores and fractures when performing waveform inversion directly for fracture parameters.