Abstract: Considering the varying lithofacies and lithology of the near-source glutenites in the Dongying sag, a three-dimensional geological model of the glutenites was established for wide-azimuth seismic forward modeling. Using the simulated data, and through azimuthal stacking of gathers in OVT-domain, the effects of azimuth variation on parameters such as seismic travel time and amplitude were analyzed, and the relationships between azimuth/amplitude and favorable reservoirs were established. The results show that the variation in the sedimentary direction of the glutenites causes azimuth differences in seismic wave propagation, leading to azimuthal anisotropy in seismic reflections. The data cube obtained from azimuthal stacking at the azimuth perpendicular to the sedimentary boundaries is more sensitive to the responses of the top and internal boundaries of the glutenite,with stronger amplitudes. It more effectively reveals the contacts between glutenites of different periods,thereby facilitating the accurate identification of glutenite and fine prediction of favorable reservoir distribution. Wide-azimuth OVT-domain seismic data are proved effective in glutenite prediction,and have been successfully applied in predicting glutenite reservoirs in the steep slope zone of the northern Dongying sag,with the prediction results in good agreement with actual drilling results.

Key words: Dongying sag, steep slope zone, glutenite, OVT domain, wide-azimuth, seismic forward modeling, seismic attribute, anisotropy