双相各向异性随机介质伪谱法地震波场特征分析

各向异性、双相孔隙以及非均匀性是描述油气储层时应综合考虑的. 结合随机介质理论和双相介质模型建立了双相各向异性随机介质模型，采用伪谱法模拟了双相各向异性随机介质地震波场，结果表明：双相各向异性随机介质地震波场存在散射波、旅行时扰动等复杂的波场特征，这些特征强烈依赖于随机介质模型参数. 在大非均匀空间尺度下，非均匀幅度主要影响波的旅行时扰动；在小非均匀空间尺度下，非均匀幅度主要影响波的散射. 该研究使人们有可能在统计意义下反演油气储层的非均匀特征，有益于加深对地震波在油气储层中传播规律的认识.关键词：双相各向异性随机介质伪谱法地震波

Features analysis of seismic wave field in two-phase anisotropic random medium with the pseudo-spectral method

The anisotropy, two phase pore and nonuniformity must be considered comprehensively in order to describe the oil and gas reservoirs accurately. Consequently a two phase anisotropic random medium model based on the two phase model and random medium theory is presented in this paper. The seismic wavefield numerical modeling was simulated by using the pseudo spectral method. The results show that there exist complex wave field features such as wave scattering and traveling time disturbance and these features strongly depend on parameters of the random medium model, the nonuniformity rate mainly impacts the wave traveling time disturbance when spatial scale of nonuniformity is large and mainly impacts wave scattering when spatial scale of nonuniformity is small. The studies make it possible to retrieve the nonuniformity on statistical basis and are useful to understanding more deeply the seismic wave propagation in oil and gas reservoirs.