Numerical Simulation and Propagation Law of Seismic Wave Field in the Loess Plateau of Ordos Basin

Summary The Loess Plateau of Ordos Basin, Western China is affected by the irregular topography and strong attenuation of huge thick loess layer, resulting in extremely low signal-to-noise ratio and resolution, which greatly affects the accuracy of imaging and reservoir prediction. To study the propagation law of seismic wave and the noise generation mechanism in the Loess Plateau, we establish a 3D realistic velocity and Q model according to the actual surface elevation and velocity structure of the North Qingcheng 3D work area. We implement 3D numerical modelling of this model based on a viscoacoustic wave equation with explicitly expressed quality factor and obtain simulation results similar to the real seismic data. Through wave field deconstruction of the numerical modelling results of four models with different complexity, we gradually clarify the generation mechanism of near-offset strong energy noise, multiple reflection and multiple refraction in the simulation results. The conclusion of numerical simulation has a good guiding significance for real data processing.