双相黏弹VTI介质一阶速度—应力方程正演模拟及双程波照明研究

地层岩石具有各向异性、黏弹性及双相性等特性,因此建立更加精确的地下介质模型,研究地震波传播规律,对认识复杂介质中地震波的传播特征和实际资料的解释有着重要的实际意义.为此,基于黏弹性广义标准线性体(GSLS)模型,首先推导了双相黏弹VTI介质的一阶速度—应力方程并进行正演模拟,与单相弹性各向同性介质相比,双相黏弹VTI介...

First-order velocity-stress equation forward modeling and two-way wave illumination in two-phase viscoelastic VTI media

Rock has such properties as anisotropy, viscoelasticity and two-phase. To understand the propagation characteristics of seismic waves in complex media and interpret raw seismic data, it is of great practical significance to establish a more accurate model and study the propagation theory of seismic waves in subsurface media. This paper derives the first-order velocity-stress equation of two-phase viscoelastic VTI media and performs forward modeling based on a viscoelastic GSLS model. Compared with single-phase elastic isotropic media, seismic waves propagating in two-phase viscoelastic VTI media are more significantly atte-nuated and the wave fronts become elliptical, and slow qP waves appears. Analysis of two-way seismic wave illumination of two-dimensional two-phase viscoelastic VTI media shows that the viscoelasticity of the media attenuates seismic wave energy, the anisotropy of the media causes seismic velocity to vary with direction, and the slow qP wave caused by the two phases of the medium complicates the energy distribution of seismic waves. According to the illumination result, the observation system was optimized.