Design Of The Control Circuit Module Of Three-Dimensional Acoustic Logging Tool

As consumables, oil is continuing exploited by human beings, which leads to the exploration and logging deeper in depth and more difficult. The control circuit module is one of the most important part of the three-dimensional acoustic logging tool. It is transmission link between the ground system and the acquisition and processing module, and it is also the control center of acquisition working flow.The three-dimensional acoustic logging tool is developed on the basis of the cross dipole acoustic logging tool, which is a frontier of the acoustic logging tool in the field of acoustic logging technology. The three-dimensinoal acoustic logging tool utilizes all of the acoustic measurement modes(including monopole, dipole, stoneley wave). It can measure the waveforms of the various frequency bands. So the three-dimensinoal acoustic logging tool can abtain a full features of the underground, including the situation changes of radial, wellbore axial and circumferential in borehole. The three-dimensional acoustic logging tool characteristics include real-time logging, high-resolution and providing abundant stratum information. And all of these characteristics are based on a large number of acoustic data. Therefore the transmission system of large amount of data, with long-distance and at high-speed has become one of the key technology of three-dimensional acoustic logging tool. As communication center, realizing the high-speed transmission system is the key technology and difficulties of the control circuit module. Based on the working principle and demand of the three-dimensional acoustic logging tool, the thesis focuses on the design of high-speed transmission and the control circuit module. Firstly, the high-speed transmission system design of the three-dimensional acoustic logging tool is introduced in detail, including the topology structure of LVDS, and the design of hardware, impedance matching, 8B10 B codec etc. Then, according to the overall design based on “FPGA+DSP”, the thesis describes the design of the control circuit module in detail, including the hardware design, the EDIB and McBSP communication interface with ground system, 100 k Hz synchronous serial communication interface, the timing analysis of acquisition, software design based on DSP and logic design based on FPGA. Finally, according to the demand of the control circuit module, series of tests and results analysis are provided.Based on the practical acquisition data analysis of the three-dimensional acoustic logging tool, the feasibility of the control circuit module is verified. The design meets the demand of the three-dimensional acoustic logging tool.