2.5-D Time-Domain Seismic Wavefield Modeling in Heterogeneous Viscoelastic and Tilted Transversely Isotropic Media (2023)

Accurately modeling seismic wave propagation in complex subsurface structures is not only helpful to understanding seismic data and rock properties but also the fundamental part of seismic full waveform inversion to image subsurface geological structure. 3-D seismic wave modeling is often expensive due to the huge consumption of computer resources. Alternatively, an efficient and accurate 2.5-D wave modeling can be employed for obtaining the 3-D wavefield in a 2-D geological model that is often encountered in practice. We present two advanced numerical methods for the 2.5-D viscoelastic anisotropic wave modeling by integrating three innovations. First, we formulate the 2.5-D viscoelastic anisotropic wave equations, particularly for a heterogeneous tilted transversely isotropic (TTI) medium that represents many sedimentary and igneous rocks of the subsurface. Second, we extend the common memory variable method and propose a new generalized recursive convolution (RC) method to the 2.5-D wave modeling. Third, we demonstrate the real-domain fully parallelized computing of the two methods to gain high computational efficiency of wave modeling. Our calibration experiments validate the accuracy of the proposed methods, and our modeling of a benchmark geological model exhibits the capability of the proposed methods to simulate the 3-D wavefield in a complex 2-D heterogeneous viscoelastic anisotropic medium. Such robust numerical simulations may enhance the characterization of seismic wave propagation and high-resolution subsurface imaging through full-waveform inversion, which is applicable for seismic exploration, the seismological study of the earth's interior, and geohazard detection.