应用一种新的积分方程算法对各向异性地层频率域电磁测深三维问题进行正演模拟.利用范数小于或等于1的修正Green算子得到各向异性地层中的新积分方程,由于满足压缩映射条件,该积分方程在任意参数条件下总是迭代收敛的.提出一种应用迭代法求解新积分方程的迭代初值优化选择方法,并通过具体算例对比说明该方法可使频率域电磁测深三维模拟的计算效率得到有效提高.最后应用所述算法对层状各向异性大地轴向频率测深视电阻率响应进行三维数值模拟,考察分析地层的各向异性对视电阻率响应特征的影响,得到一些重要结论.
We carry out three-dimensional(3-D) modeling of frequency electromagnetic sounding in layered anisotropic earth using integral equation method. A integral equation formulation is derived based on modified Green’s operator with norm less or equal to one. The integral equation is convergent for any conductivity distribution and frequency if iterative solvers are used. An optimal choice method on initial guess for iterative solvers is introduced. It improves computational efficiency of 3-D modeling of frequency electromagnetic sounding significantly. Apparent resistivity responses of 3-D axial frequency electromagnetic sounding are considered in multilayered anisotropic earth.