Research And Implementation Of Transceiver System Circuit In 3-D Induction Logging

In oil exploration, as with the further improvement of oil exploitation degree, demand for detection of anisotropic formation is increasing. But normal induction instrument only can measure the level of horizontal resistivity, it is easy to miss, underestimate even wrongly anisotropic oil reservoir. Because of the special structure of the coil system, for measuring the anisotropic complex reservoir parameters, 3-D induction logging has other instrument incomparable advantage. The research background of this paper is the research and development of 3-D sensing instrument engineering prototype. This thesis is mainly focused on the research and design of transceiver system. The major works are listed as follows:(1)According to the three-dimensional induction coil structure, the specific function and technical index of circuit, design the overall solution and structure of transceiver system.(2)Because the receiving coil is decorated in nine position, induction signal is weak, and the dynamic range is big, at the same time logging instrument circuit board frame space is very limited. To solve these problems, this thesis designs the multi channel selection and classification gain receiving circuit which implements the acquisition and processing of 21 large dynamic range signal.(3)For emission circuit, signal launched in both frequency and three directions respectively. This paper designed the launch control circuit with A3P060 FPGA and MSP430 as the core; at the same time, design and develop the application control program which realized the function of the choice of the direction and switching frequency.(4)Instrument is faced with the challenges of the high-temperature, high pressure and high vibration environment, while in order to improve the heat stability of emission current. This thesis designs a class D power amplifier whose current is adjusted, which enhance the stability of the system at high temperature.(5)Finally, debug the hardware and software of each PCB. Then 3-D sensing instrument including transceiver system, power board and main control board does the joint debugging. High temperature test during a long time shows: In the high temperature, the experimental data is stable and reliable; Three-dimensional sensing instrument has preliminarily log function; The transceiver system circuit has achieved the scheduled technical requirements, which laid a solid foundation for the actual logging.This research has laid a solid foundation for the development of 3-D induction logging tool. Now the three-dimensional induction engineering prototype has entered the actual logging debugging stage.