3D Superwide-angle One-way Propagator And Its Application In Seismic Modeling And Imaging

Traditional one-way wave-equation based propagators have been widely used in theoretical researches and in practice in past decades. Comparing to two-way propaga-tors, one-way methods have higher efficiency and lower memory demands. These two features are especially important in solving large-scale 3D problems. However, regu-lar one-way propagators cannot simulate waves that propagate in large angles within 90° because of their inherent wide angle limitation. Single one-way can only propagate along the determined direction (e.g., z-direction), so simulating of turning and reflect-ing waves is beyond the ability of one-way methods. We develop 3D superwide-angle one-way propagator to overcome angle limitation and simulating turning waves with superwide-angle propagation angle (> 90°) for modeling and imaging complex geo-logical structures. Wavefields propagating along vertical and horizontal directions are combined using typical stacking scheme. A weight function related to the propaga-tion angle is used for combining and updating wavefields in each propagating step. In the implementation, we use graphics processing units (GPU) to accelerating the pro-cess. The typical workflow is designed to exploit the advantages of GPU architecture.Numerical examples show that the method achieves higher accuracy in modeling and imaging steep structures than regular one-way propagators. Actually, superwide-angle one-way propagator can be applied based on any one-way method to improve the effects of seismic modeling and imaging. Finally, even though the computational costs and the memory demands of superwide-angle approaches are worse than the regular one-way proapgators, they are much better than the two-way methods.