【摘要】 基于BISQ模型,分别推导出二维平面内双相各向异性介质中拟快纵波(qP1)、拟慢纵波(qP2)、拟SV波(qSV)和拟SH波(qSH)的波数方程。通过计算机数值计算得到四种类型波的相速度与逆品质因子,在极坐标系中观察地震波速度和衰减随波传播方向的变化规律,发现四种波的各向异性特征表现不同,且衰减各向异性特征表现得比相速度更为强烈。文中分析了孔隙度、黏滞系数、渗透率和喷射流长度等参数在垂直方向以及全传播方位角范围对四种类型波的相速度和衰减的影响,发现这种影响也存在各向异性特征,还分析了不同参数条件下波场特征随频率变化的特性,得出一系列有意义的结论。更多还原

【Abstract】 Based on BISQ model,the paper deduced the wave number equation of pseudo-fast P-wave (qP1),pseudo-slow P-wave (qP2),pseudo-SV-wave (qSV) and pseudo-SH-wave respectively in biphase anisotropic medium in 2-D plane. It is discovered by phase velocity and inverse quality factor of 4 kinds of wave computed by numeric simulation of computer and changing rule of seismic wave velocity and attenuation along with propagation direction in polar coordinate that there is different performance of anisotropic feature in 4 kinds of wave and the anisotropic feature of attenuation showing stronger than that of phase velocity. The paper analyzed the influence of different parameters such as porosity,viscosity coefficient,permeability and jet stream length on phase velocity and attenuation of 4 kinds of wave in vertical direction and full-propagating azimuth region,which discovered that the influence also has anisotropic feature. Meanwhile,the paper also analyzed the characters that the wavefield changes with frequency in different parameter conditions and gained a series of meaningful conclusions.更多还原