The Research And Design Of An Array Laterlog Resistivity System

After the development of dual laterolog, array tool has been constructed.Laterolog array is a new type of multi-probe depth array instrument, which isdesigned and developed for the identification and evaluation of complexreservoirs. The array resistivity tool has become one of the most hot researchinstrument in oil well logging services companies at home and abroad. Atpresent, only a handful of companies have this type of instruments, Therefore,the development of the array laterolog instrument system with independentintellectual property rights has a significant meaning as well as economic value.Logging tools work in the adverse circumstances with high pressure andhigh temperature, requires the instrument has an excellent stability, whichgreatly increase the difficulty of the instrument design. This paper brieflyoutlines the resistivity logging technology development, analysis of theadvantages and shortcomings of different resistivity logging technology,combined with the actual needs of instrument, design and built laterologresistivity logging system instrument circuitry with seven vertical resolution,large dynamic range. With in depth analysis the system function andperformance，a practical system with TMS320F2812DSP controller and A3P250FPGA as key hardware system and the software has been builted.The maincircuit blocks including: Seven channels sine signal sources、transmitter signalmonitoring、electrode driving、weak signal acquisition and processing、systemstate controller and communication. The system has been debuged, tested,achieved the desired design requirements that laid a solid foundation for theengineering application of the array tool.