非均匀各向异性介质地震正演模拟新方法

A new method of seismic forward modeling in heterogeneous and anisotropic media

文中提出了有助于模拟地下多尺度非均匀各向异性介质的地震正演模拟新方法——微观矢量微分方程加宏观标量微分方程(MIVMAS)。该方法以介质的等效参数为基础,运用微观矢量微分方程计算小尺度非均匀和(或)各向异性介质的等效参数,利用等效参数具有的宏观性,与表征大、中尺度的地质体参数一起构成复合地质模型,最后用宏观标量波动方程对复合地质模型进行地震正演计算。为检验MIVMAS方法的实用性,设计了一个与实际地质、地震条件类似的地质模型,该模型包含碳酸盐岩潜山顶面的复杂上覆层和潜山内幕的缝洞系统,用MIVMAS数值模拟获得了理想的效果,证明了该方法的有效性和实用性。

A new method aimed to implement muhi-scale seismic modelling of heterogeneous and anisotropic media has been proposed in this paper and it is named the microcosmic vector differential equation and the macroscopic scalar differential equation （MIVMAS）. Basic idea and main steps for this modelling are as the following： calculating micro-scale properties of seismic wave propagated through heterogeneous and anisotropic media by using the microcosmic vector differential equation and expressing those micro-scale pn）perties with equivalent parameters in macro space; building a macro-scale model based on given geological structure and equivalent parameters; implementing the seismic modelling of model by using acoustic （or scale） wave equation. In order to verify the practical applicability of MIVMAS, the geological model similar with real geological and seismic condition is designed. This model includes the fractured-vuggy system of complex overlying strata and the inner of the carbonate buried-bills. An ideal effect has been obtained by MIVMAS numerical simulation, proving the validity and practicability of this method.