Design And Implementation Of Data Acquisition & Processing System In Mci Logging Tool

The design and implementation of date acquisition & processing system in MCI (Micro Conductivity Imager) logging tool has been expounded in this thesis. The system is an important part of MCI logging tool. Acquisition & processing of signal form buttony electrode and assistant parameters, transmission of information with R&S section via CAN BUS is major functions of the system. To improve the capability, such as, measuring range, precision, heat-resistant and compression-resistance capability, of homemade MCI logging tool is the main purpose of this research.After the Requirement analysis of the research, technical precept has been made, which compartmentalized the system to two modules called master DSP module and slaver DSP module. In master DSP module, system scheduling, management of date transfer, acquisition & processing of assistant parameters, and high speed(500Kbit/s) transmission of information accomplished via CAN BUS have been finished. In slaver DSP module, acquisition & processing of signal form buttony electrode has been finished. One of the important content of this thesis is the design of algorithm to digital phase sensitivity detection. Though analysis of frequency response, the most calculated sampling cycle and point number have been chose, which has harmonized distribution problem of acquisition time and processing time, and assuaged the conflict between huge amount of measuring information of buttony electrode signal and the request of high precision. In the process of MCI logging tool'associated debugging, we found that, grounded points were mixed and disorded, noise has been imported from ground wire. After analysis of the noise, use ground point suspension technique, insulated logging tool's ground wire from date acquisition & processing system's ground wire, restrained ground wire noise.The results of indoor experimentation can justify that, the final results of three measuring modes of acquisition & processing system is linear, and the result trendlines of three measuring modes are accordant. It shown that, the measuring result of the system can reflect reality. In field tests of CQ test well, measuring image's characters are accordant compared with overseas logging tools, details of image are more clearly than primary MCI logging tool. In the field tests of Ren91# test well (4000m depth), heat-resistant capability and compression-resistance capability have been substantiated.