层状介质二维井间电磁成像  

Two-dimensional crosshole electromagnetic imaging of layered media

作　　者：邵长金[1] 李相方[1] 

机构地区：[1]中国石油大学石油天然气工程学院,北京102249

出　　处：《石油大学学报（自然科学版）》2005年第2期25-29,共5页Journal of the University of Petroleum,China(Edition of Natural Science)

摘　　要：根据分层介质中波的传播规律,利用均匀介质中的三维张量格林函数推导出二维情况下分层介质的张量格林函数,它是一个对kx的一维Sommerfeld积分。准确求取这一积分后,可以方便地利用迭代等方法反演出井间的电导率。给出了利用上行波和下行波方式表达的界面反射和折射张量函数及其各分量。通过积分方程方法对埋置于有8个分层的两个垂直方向电导率异常体模型进行了计算,反演结果与原模型基本吻合,有效地实现了层状介质中二维井间电磁成像。The two-dimensional Green tensor for layered media was deduced from the three-dimensional Green dyadic for homogeneous according to the propagation laws of waves in layered media. The tensor is one-dimensional Sommerfeld integral over k\-x. After the integral has been precisely valued, the electric conductivity of the media laying between the holes can be inversed by the methods such as iteration or others. Each component of the tensors representing the reflection and refraction at the interfaces were expressed in the form of upgoing and downgoing wave. Using the integral equation method, a case of two vertical abnormal conductors embedded in a 8-layered medium was calculated. The inversion image well matches the original model, showing that the mentioned method can perform two-dimensional crosshole electromagnetic imaging well for layered media.

关 键 词：井间电磁成像 层状介质 二维 张量格林函数 积分方程方法 分层介质 电导率异常 传播规律 均匀介质 张量函数 界面反射 垂直方向 下行波 上行波 体模型 模型基 反演 

分 类 号：P631.813[天文地球—地质矿产勘探] P631.4[天文地球—地质学]