Common Seismic Models Used in Seismic Data Processing

Common seismic models in seismic data processing serve as essential tools for understanding and analyzing seismic wave propagation patterns. They provide the theoretical foundation for seismic data simulation, inversion, and interpretation. In seismic exploration and research, these models help researchers validate algorithms, test data processing workflows, and understand wavefield characteristics under complex geological structures. The following are several common seismic models:

Acoustic Medium Model This model is based on the acoustic wave equation, assuming only compressional waves (P-waves) exist in the medium while ignoring shear waves (S-waves). It is suitable for basic seismic simulations, such as marine seismic exploration where S-waves are weak, primarily focusing on P-wave propagation characteristics. Implementation typically involves solving the 2D/3D acoustic wave equation using finite-difference methods with staggered-grid schemes.

Elastic Wave Medium Model Unlike the acoustic model, the elastic wave model considers both compressional waves (P-waves) and shear waves (S-waves), making it suitable for more complex geological environments like land exploration or fault zone studies. This model can simulate wave propagation and mode conversion phenomena in heterogeneous media. Code implementation often uses the velocity-stress formulation with fourth-order finite-difference operators for accurate wavefield simulation.

Layered Medium Model This model assumes subsurface media consist of a series of horizontal or inclined homogeneous layers, each with different velocities and densities. The layered model is commonly used to study reflection and refraction wave propagation patterns and serves as a simplified model in seismic data processing. Algorithm implementation typically involves recursive reflectivity calculations or matrix propagation methods for multilayer systems.

Anisotropic Medium Model In reality, subsurface media often exhibit direction-dependent elastic properties, such as in shale or fractured reservoirs. Anisotropic models can simulate velocity variations when seismic waves propagate in different directions, which is crucial for accurate seismic data interpretation. Implementation commonly uses Thomson parameters or weak anisotropy approximations with rotated staggered-grid finite-difference schemes.

Attenuating Medium Model Seismic waves may experience energy attenuation due to medium viscosity and scattering effects during propagation. This model introduces quality factors (Q-values) to describe medium attenuation characteristics, making it suitable for studying high-frequency seismic wave absorption and dispersion phenomena. Code implementation often incorporates viscoelastic rheological models using memory variables or Zener mechanical models.

These seismic models can be computed using various numerical simulation methods (such as finite-difference method, spectral element method, etc.) to simulate seismic wave propagation characteristics under actual geological conditions. Researchers can select appropriate models based on specific problems and conduct in-depth analysis combined with seismic data processing techniques. Modern implementations often utilize parallel computing frameworks like MPI or CUDA for large-scale 3D simulations.