Design Of Focus Multi-parameter Logging Tool

In the process of formation water resistivity logging, well hole is full of mudand drilling fluid, the resistivity of mud and drilling fluid is very different from theresistivity of formation, If measured regarded as one kind of material, the resistivitymeasurement results will be error. Use the principle of Induced polarization measure theformation water resistivity, combined with mud resistivity logging, Can rule out theinfluence of mud and drilling fluid with the result of well logging. Using ordinaryresistivity logging sonde, detecting depth is small, logging efficiency is low. In order toovercome the above shortcomings, we adopt dual laterolog sonde replace ordinaryresistivity logging sonde.Based on the principle of induced polarization logging and dual lateral loggingprinciple, this thesis proposes a new design of multi-parameter logging tool. Usinginduced polarization incentives and dual laterolog sonde structure, using fieldprogrammable gate array (fpga) and digital signal processor to control instrument and thecombination of data processing, make logging tool can work automatically. In this thesis,the logging instrument hardware circuit and software are modular design, functionallysimilar or have a high correlation between part is divided into a module, this thesisintroduces the design of each module.According to the principle of induced polarization and dual laterolog measurement,designed the process of focusing induced polarization measurement, according to thelogging process design the control sequence of all parts of the instrument, and write DSPand FPGA control program accordingly. DSP as a bridge of ground control system anddownhole measurement instruments, DSP adopts CAN bus communication protocol datainteraction with ground control system, ensure the data transmission distances andefficient.