Frequency Induction Logging Tool Measurement Circuit Design

Logging has been developing because of the special demand of oil industry for evaluating the oil storage. Logging can be explained as a log of stratum characteristics by using measurement equipment. Logging means difference for different people. For rocksy, logging is mainly a kind of underground prospecting technology. For rock physical scientist, logging is a way evaluating oil throughput. For logging engineer, maybe logging just provides numerical value for simulating applications.After over 70 years'development, electric logging has become an independent subject. Developed from the spontaneous potential logging to induction logging and array induction logging which are very popular today. Induction Logging is an important method of resistivity measurement. With the development of the foundation theory research and Induction Logging tools, Induction Logging technology is getting more and more application and attention. The numerical value simulation research of Logging response had been from one dimension to two dimensions,now to three dimensions complex model. Induction Logging Tool had developed from traditional analog one to digital vector one, and soon been to Array Phase Induction Logging Tool with several frequencies.Dual Frequency Induction Tool (DFIT in short) referred to in this thesis is a created new one which is based on the wave theory and Array Phase Induction Logging Tool. It is a resistivity logging Tool by measuring two relative parameters, Amplitude Ratio and Phase difference of the electromagnetic wave signal. Measurement circuit of DFIT is designed in this thesis, including data acquisition, data storage and processing, also data transmission. In the first chapter, the development history and status in and abroad of Induction Logging are expatiated on, the technology characteristics and research significance of DFIT are discussed, the task and target of this thesis are given. The foundation theory and the whole scheme of DFIT are expatiated on in the second chapter. In the third chapter and fourth chapter, hardware and software are designed, the principle of phase difference measurement in digital correlation method is discussed, the precision and affecting factors of phase difference measurement are analyzed, the particular arithmetic is given, both the simulations and the experiment results prove the feasibility and effectiveness of the arithmetic. In the fifth chapter, the experiment results done in the sampling well are discussed, the Logging curve is contrasted with Russian Induction Logging tool VIKIZ which is designed according to equal parameter condition. The experiment results prove the correctness and feasibility of the design. In the sixth chapter, the task of this thesis is summarized, something what I has learned is given.