Measuring Device Of Horizontal Component Of Three-component Coil Array

The formation resistivity is an important parameter for the identification and evaluation of reservoir and induction logging is the most conventional method to obtain the formation resistivity.Three-component induction logging is a new kind of detecting toll,which is mainly used to detect anisotropic reservoirs.This tool can not only measure the resistivity in vertical direction but also can measure the resistivity in horizontal direction.The horizontal coil of three-component coil is completely different from the traditional vertical coil.The measuring device of horizontal component in three-component coil is designed in this thesis.The device is mainly used to measure the horizontal coil to get the horizontal component information.Meanwhile,the vertical coil can also be measured with this device.The device can be used measure the receiver voltage of the horizontal coil and vertical coil and analyze the response characteristics,which provide the experimental basis for the true tool design.The following is the maim contents and results.The first part in this thesis mainly studies the theory of dual induction logging and the theory of three-component induction logging.The overall structure and the coil structure of the measuring device of three-component coil of horizontal component are designed according to the technical specifications.In the second part,the transmitting circuit of the measuring device of three-component coil horizontal component is designed,including module design of waveform generation,differential amplifier design and power amplifier design.Design a minimum system circuit based on the chip TMS320F2812,AD9833 circuit and differential amplifier circuit.Discrete component is adopted to set up power amplification circuit to achieve power amplification of signal source.As for the software design of the transmitter circuit,TMS320F2812 is used to control AD9833 chip to produce sine wave of 6KHz and 18 KHz and the main program will be provided.The receiving circuit of the measuring device of three-component coil horizontal component is designed in the third part.Hardware circuit includes pre-amplification filter circuit,AD acquisition circuit and data transmission circuit between the Field Programmable Gates Array(FPGA)and Digital Signal processing(DSP).The software design of receiving circuit includes that FPGA controls AD7606 chip to collect data,FIFO is made inside FPGA to collect data,inform DSP read data through interrupting,and DSP uploads the data to upper computer fordata processing.After system tested,the data meets the technical requirements.The three-component induction measuring device designed in this thesis can be used to analyze the number of coils both in the horizontal and vertical direction,the distance between coils,coils' arrangement form and the effects of coil limit length on measuring circuit.The response characteristic of different input frequencies can also be analyzed.