| It is significant to develop the new-type well logging theory and bring it into implementation for the complex oil and gas wells. The technology of Multi-frequency Induction Amplitude and Phase Logging has the characteristics of high resolution and simple tool structure, and the phase differences and amplitude ratios are measured in the MFIAPT (Multi-Frequency Induction Amplitude and Phase logging Tool). Nowadays the MFIAP (Multi-Frequency Induction Amplitude and Phase logging) technology has been developed with the LWD (Logging While Drilling) technology, and the technology and tools are patented to some foreign companies such as Atlas and Schlumberger in America as well as Lucci in Russia. However, the domestic companies and institutes are still in the stage of scientific research and lagging behind the foreign ones.During the study to the Ph.D, the author has been participated in several projects to research the MFIAP technology and its implementations. In this dissertation, the basic theory of MFIAP, the theory of the frequency selection and spacing selection and the implementation of the MFIAPT are researched in detail. And the main inovations and contributions are as follows:(1) The relationship between the transmitter frequency and the spacing as well as the radial detection depth and the vertical resolusiotn is dicussed systematically. Some factors should be considered in the transmitter frequency selection, as the maximum transmitter frequency of induction logging is determined by the Quasi-steady electromagnetic field, the propagation effects and the impact of probing depth, and the minimum transmitter frequency is determined by the SNR requirements. In the research for the realization methods and technology of MFIAP, the above results give the theoretical basis for the design of the transmitter and receiver coils system of the MFIAP tool.(2) From the previous related research, the analytical expressions of the most important two measurements of the MFIAP tool, phase difference and amplitude ratio are derivated based on the electromagnetic field theory and the Maxwell's equations. And the theory of MFIAP is presented in detail. Then the MFIAP tool's coil system is designed based on the theory of frequency selection and spacing selection. Thereafter the three-coil array's response functions are researched and its detection responses in typical stratum are simulated. At the same time, the tool's calibration principle, its implementation and the design parameter are studied. All the above can support the realization of MFIAP, namely the design of the MFIAP tool in theory.(3) Considering the logging tool structure and the operating frequency, the adaptive boreholes correction method for the two-dimensional rotationnlly symmetric medium is built based on the realization method of MFIAP. The correction method by means of data query can correct the errors of the phase difference and amplitude ratio caused by the variations of the borehole size and the mud resistance. In the measurement circuit design, an improved digital correlation method is developed to measure the phase difference and the amplitude ratio. And the problem of measuring the negative phase difference in the basic correlation method is solved by this improved one.(4) The control and operation time sequences of the MFIAPT are designed in detail considering the characteristic of the MFIAPT's structure. The analysis and design of the MFIAPT's circuit units are carried out including the control and communication circuit, the data acquisition and processing circuit, the signal generation and control circuit and the electromagnetic signal driving circuit. Then the design and the implementation of the MFIAPT are completed.(5) Logging experiments of the MFIAPT are carried out in the oil field. The tool gives fine logging curves with correct trend and high SNR. The curves are accord with the standard data of the oil well, and they can reveal the characteristics of the real formation. So the theory presented in this thesis is verified. |
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