微柱形聚焦测井响应特性分析

The Analysis of Response Characteristics of Micro Cylindrical Focused Logging

为了分析微柱形聚焦测井响应特性,根据微柱形聚焦测井测量原理,利用有限元方法,在三维介质中建立地层模型,分别研究微柱形聚焦测井在地层中的电压电流分布、回路阻抗、仪器常数、径向探测深度和纵向分辨率等响应特性。研究表明,仪器金属外壳对测井响应有一定的影响;三个纽扣电极的测井响应对地层电阻率的敏感度非常好,而且具有很好的线性度;测量的三条电阻率曲线径向探测深度浅,能反映冲洗带的特性,径向分布均匀合理;纵向分辨率高达2cm,有利于薄层评价。

In order to analyze the response characteristics of micro cylindrical focused logging,the stratum model in three-dimensional medium is established by using the finite element method according to the measurement principles of micro cylindrical focused logging.This paper studies the characteristics of the voltage and current distribution,the loop impedance,the instrument constant,the radial investigation depth and the resolution.Research shows that the metal shell has some influences on the log response;the sensitivity of the three button electrodes to the formation resistivity is very good and it has good linearity;the three measured resistivity curves that detect radially the depth can reflect the characteristics of flushed zone and the radial distribution is reasonable;the vertical resolution is up to 2cm,which is good for thin-bed evaluation.