Frequency Dependent AVAZ Induced by a Single Fractured Thin Bed
H. Liu, X. Li and S. Chen
Event name: 80th EAGE Conference and Exhibition 2018
Session: The Resolution Of Anisotropy I
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 9.79Mb )
Price: € 20
Frequency-dependence of anisotropy can be caused by physical properties of fractured porous rock and tuning effect. In this paper, we perform a synthetic study to talk about frequency-dependence of anisotropy induced by these two factors but we pay more attention to tuning effect. We use reflectivity method to generate azimuthal gathers for P-wave based on Chapman’s multi-scale rock physical model and use SPWVD to apply spectrum decomposition to compare characteristic of anisotropy for different frequency components. Based on the work, we find anisotropy intensity for a single fractured thin bed is constrained by thickness, the difference of energy and characteristic of azimuth anisotropy for the top and bottom interface reflections. Anisotropy intensity varies with frequency periodically, and the period is determined by thickness when the dominant frequency of the wavelet is a constant. Characteristic of frequency-dependent anisotropy induced by rock properties can be covered up by that of tuning effect. So we can’t neglect tuning effect when we try to use frequency-dependent azimuth anisotropy to describe fractured reservoirs.