Azimuthal Variations of Attenuation Analysis Applied on a 3D Multi-azimuth Towed-streamer Dataset

Knowledge of key fracture properties at reservoir level such as their dominant orientation is important for successful hydrocarbon exploration since it can help enhance oil recovery. A common method to determine fracture orientations is by means of the analysis of amplitude variations with offset and azimuth (AVOA). Unfortunately inferred results are not unique and a 90 ambiguity in fracture orientations can exist – even if solely a single major trend is present. Like amplitudes, attenuation also exhibits azimuthal variations in the presence of fractures and/or cracks. The analysis of attenuation variations with offset and azimuth (QVOA) thus holds complementary information to AVOA inversion results. This paper discusses a methodology used to extract variations of attenuation on a 3D multi-azimuth sectored dataset. This methodology is also applicable to both multi-azimuth walkaway VSPs.