3D Quantitative Ava: A Model-Based Approach For A Joint In V Ersionof Angle Data

In order to provide a user guided and quantitative approach to AVA integrated processing, we propose a model-based approach to jointly invertangle-limited stacks. In a first step, we use a multi well calibration analysis to extract a single wavelet for each angle stack volume. Then, we use an elastic inversion approach based on a 3D formalism in which a priori information<br>is provided for each parameter (P- and S-impedance). For both calibration and inversion purposes, the Knott-Zoeppritz equation is used to compute the predicted synthetic data associated to a specific incidence angle. The inversion involves the computation of a global objective function which is minimized in order to compute an optimal model for each elastic parameter. This<br>model best explains the AVA information of the angle stacks and the stratigraphic/petrophysics knowledge introduced through the a priori information. The method is illustrated on a real 3D marine case study.