Design Of Real-time Data Processing For LWD Logging Tool And A Research On Flash Equalization Algorithm

Logging-While-Drilling(LWD)refers that logging tools go down the well with the drill bit,performing logging and transmitting the measurement results to the surface in real time.One of the representative technologies is the Density LWD,which is the research content of this thesis.The real-time nature of logging results is a unique advantage of LWD technology,but it also has high requirements for the real-time data processing capabilities of the instrument.Real-time data processing includes the calculation and storage of original data.The lower the correlation between calculation and storage,the higher the stability of the data processing process..The Flash wearleveling aims to use a certain strategy to make each block of the Flash memory wear evenly,and to extend the life of the Flash to the greatest extent.Through the analysis of the requirements of the data processing structure,this thesis has determined the basic hardware framework of data processing,that the MCU is the main controller and the FPGA is the basic structure of the data buffer.Through the analysis of downhole data storage requirements,the storage hardware framework of multiple Nor Flash cascades is determined.Combined with other requirements,the hardware scheme design of the data processing module is finally completed.Then,according to the functional requirements of the data processing module,the software logic design is completed,which mainly includes data processing logic design,communication logic design and storage logic design.Next,the research of Flash wear-leveling gradually introduces the background and basic implementation methods of the Flash wear-leveling.Then several current mainstream methods are introduced and compared,and combined with the data characteristics of the Density LWD,the application of Flash wear-leveling in the data processing module is realized,and the effect analysis is good.Finally,the thesis introduces a series of verification tests for the data processing module of the Density LWD,including functional tests and harsh environment tests.The Functional tests aim to verify the module's functions like communication,data upload,data storage and so on.While the purpose of harsh environment tests is to test the working stability of the instrument in the actual environment.The test results show that the command response and data upload speed of the data processing module can reach millisecond level and the data processing module can work steadily in the high temperature environment of 140? and the strong vibration environment of 5G,which shows that the design can be used in actual projects.