Dependency of AVO and AVOA Signature for long-offset P-wave Seismic Reflections in the Vicinity of Volcanic Structures
M.A.A.M. Jelani and D. Angus
Event name: 78th EAGE Conference and Exhibition 2016
Session: AVO-AVA Theory (A)
Publication date: 31 May 2016
Info: Extended abstract, PDF ( 1.36Mb )
Price: € 20
It is generally understood that imaging within the vicinity of the volcanic structures, such as the seaward dipping reflector (SDR) has been a difficult task. This is mainly due to the highly heterogeneous, systematic layering and stacking of basalts that has led to an effective transverse isotropic anisotropy within the SDR structure. Hence, wide-angle and wide-azimuth reflection seismic survey is one of the best techniques to use as it can record a lot more information compared to conventional reflection seismic surveys (e.g., greater offset and azimuthal measurements for travel-time differences and reflection amplitude variations). This is especially important for the identification of anisotropic features. In this paper, conceptual seismic models of the SDR geometry are created in order to analyse the variation of reflection coefficients with respect to different magnitudes and symmetries of fabric-induced anisotropy. Specifically, we seek to analyse whether the seismic amplitude response and critical reflections at dipping reflector show significant variations with azimuth with respect to the different top SDR horizon geometry. Based on our results, we conclude that azimuthal analysis of seismic amplitudes is influenced by the degree and type of anisotropy as well as by the geometry of the top and bottom horizon of reflector.