New aspects of through‐casing resistivity theory
New aspects of through‐casing resistivity theory
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DOI：
10.1190/1.1444327
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发表时间：
1998-02
期刊：
影响因子：
3.3
通讯作者：
B. Singer;K. Strack
中科院分区：
文献类型：
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作者：
B. Singer;K. Strack
给出了过套管电阻率测量基本模型的闭合解，该解揭示了测量的基本特征以及这些特征对套管和地层参数的依赖性。我们开始我们的考虑与附近的一个单一的电极激励套管的电流分布的分析。该分析表明，在距离注入点仅几个半径的距离处，分布变得轴对称。因此，如果测量电极不被放置得太靠近感测电极，则用于注入电流的电极的数量和物理位置变得不重要。我们还推导出一个封闭形式的解决方案，电流分布在一个均匀的套管嵌入均匀的地层。这种考虑导致了指定所谓特征长度的表达式。电场电位作为一个功能的分析…
A closed‐form solution for a basic model of the through‐casing resistivity measurement is found. The solution reveals fundamental characteristics of the measurement and the dependence of these characteristics on the parameters of the casing and formation. We start our consideration with an analysis of the current distribution in the vicinity of a single electrode energizing the casing. This analysis shows that the distribution becomes axially symmetrical at a distance of just a few radii from the injection point. As a consequence, the number and the physical location of the electrodes used to inject electric current become unimportant if the measurement electrodes are not placed too close to the sensing electrodes. We also derive a closed‐form solution for the distribution of the current flowing in a homogeneous casing embedded in a homogeneous formation. This consideration results in an expression specifying the so‐called characteristic length. The electric field potential is analyzed as a function of th...