| 摘要: |
| 数值模式匹配(NMM)法是电法测井数值模拟的有效方法，但是由于其在解析部分要推导反射矩阵和透射矩 阵公式,因而比较烦琐。以非均匀层状介质中感应测井为例，探索了径向上数值、轴向上解析数值模式匹配理论，并 对解析部分进行了改进,即应用电场强度和磁感应强度在界面的连续性条件推导出了上行波和下行波的递推关系， 并提出了界面转换阵的概念。其思路简单，具有更加明确的物理意义，易于编程实现。经对比，新算法的数值模拟 结果与原来的NMM方法和有限元方法(FEM)的计算结果是一致的。而且，这一思想同样适用于电极型测井方法 的数值模拟，对于精确反演也具有重要意义。 |
| 关键词: 非均匀层状介质 数值模式匹配理论 感应测井 界面转换阵 计算方法 |
| DOI： |
| 分类号: |
| 基金项目:中国石油大学博士创新基金资助项目(B2005-01) |
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| An improved numerical calculation method for induction log response in inhomogeneous stratified media |
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TAN Maojin, ZHANG Geng-ji
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(Faculty of Geo-Resource and Information in China University of Petroleum.，Dongying 257061，Shandong Province，China )
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| Abstract: |
| Numerical mode-match(NMM) method is an efficient technique for numerical stimulation of electrical logs. But the existing methods are complicated and puzzled because of derivation of reflection and transmission matrices. A new type of NMM, analytic radically and numeric vertically, is optimized for numerical stimulation of induction logs in inhomogeneous stratified media. It induces potential formula between the adjacent layers recurring to the continuity of electric-field intensity as well as magnetic induction density, and brings forward a transition matrix on boundary of two layers rather than previous method about reflection and transmission matrixes in analytical section. The theory has concise physical meaning and is easy for programming. In given models, the new method proved to be highly precise and effective compared with finite element method (FEM) and previous NMM method. The results agree well with those of the previous method. Furthermore, the theory about NMM is suitable for other electrical logs and is also profound to precision forward and inversion of resistivity logs. |
| Key words: inhomogeneous stratified media numerical mode-match (NMM) theory induction log boundary transition matrices calculation method |
