多频幅相感应测井仪线圈系设计

Design of coil system for multi-frequency induction amplitude-phase logging tool

本文研究了一种全新的多频幅相测井仪的线圈系设计。文中首先通过研究三线圈系的响应函数,分析测井响应与发射频率和源距的关系,得出探测深度随频率的增加、源距的减小而变浅;分辨力随频率的减小、源距的增大而迅速变差的结论。在此基础上,设计了多频幅相测井仪的线圈系模型,并在典型地层中模拟了幅相测井仪的探测特性。实验结果表明仪器探测深度达到了3m,分层能力达到了30cm,满足仪器性能指标的设计要求。本文的研究工作为后续测井仪器的设计提供了理论依据。

A coil system for novel Multi-frequency Induction Amplitude-phase Logging Tool is studied in the paper. The three-coil system＇s response functions are researched and the relationship of the logging response with transmitter frequency and spacing is analyzed. It draws a conclusion that the investigative sensitivity goes shallow with the increase of the transmitter frequency and the decrease of the source distance, while the vertical resolution goes rapidly worse with the decrease of the transmitter frequency and the increase of the source distance. Based on the conclusion, a fundamental model of coil system for logging tool is presented. An experiment which simulates the investigating characteristic is done in the typical stratum. The experimental result shows that the investigative sensitivity reaches 3m and the vertical resolution achieves 30cm. The equipment performance can meet the design requirements. The research work in this paper provides a valuable reference on the design for induction logging tool.