【摘要】 应用有限差分法对井中激电进行三维正演,并以井中激电地-井方式为例,构造出在直流点电流源作用下三维半空间区域中异常体的正演模型;采用了超松弛迭代法提高迭代速度,运用Matlab的GUI编程实现交互式操作,解决了不规则异常体的构建问题;以井旁三维球体为算例,将数值法正演结果与解析法对比,结果表明:二次异常电位差曲线能有效反映异常矿物的激发极化特征。因此采用这种有限差分的模型进行井中激电三维正演可以准确反映异常体的激发极化特性,并能够应用到各种不规则体的正演中。更多还原

【Abstract】 A numerical model of induced polarization(IP)borehole using finite difference method(FDM)was developed to solve the forward problem of three-dimensional arbitrarily shaped objects.A surface-downhole IP measurement was simulated in half space containing an arbitrary shaped causative body.A direct point source was located on the surface,and overrelaxation was adopted to accelerate computing.Matlab GUI programming was used to construct arbitrary 3-D geometry through interactive operation.We investigated a 3-D sphere near borehole as a case study,and calculated the secondary potential difference curves both with this model and with analytical method.The comparison indicates that IP borehole measurement with this model has high precision,and is suitable for any arbitrarily shaped object.更多还原