Design And Implementation Of Detecting System For Circumferential Borehole Ultrasonic Imaging Logging Tool

Ultrasonic imaging logging is an important development direction in logging technology with high imaging resolution and reflection on the borehole wall.In the process of developing CBUILT(circumferential borehole ultrasonic imaging logging tool),there will be problems in functional verification,hardware testing,software maintenance and instrument maintenance,so the design requirements of the detection system are proposed.This thesis firstly introduced the working principle of CBUILT in detail from instrument structure and logging principle;and analyed the requirements of the detection system,which is mainly used for the function verification of CBUILT's in the preliminary development,the research of the extraction algorithm when the first wave arrive time and the testing of the ultrasonic transducer performance and other functions.Then the thesis proposed the design plan of the detection system,and divided the design of the detection system into the design of the hardware system and the design of the display and control software.The hardware system of the detection system is built around the CBUILT's circuit.The circuit is the core of the CBUILT,which controls the ultrasonic transducer to emit ultrasonic waves through the position synchronization signal provided by the motor,and collects and processes the echo information,then uploads the data to the surface system through the EDIB bus.In order to fully simulate the work of CBUILT in the laboratory,the detection system selected a suitable motor and motor driver;for the communication interface used by CBUILT,the thesis completed the hardware circuit design of the communication adapter board with FPGA as the core.And logical programming,which implemented the conversion between EDIB bus interface and USB interface.Finally,the thesis designs a convenient and unified physical structure of the detection system.In order to systematically implement the display control software,this thesis applied UML language to perform requirement analysis,structure analysis and structure design of the display control software,and implemented the user interface and functional modules of the display control software based on Python+Py Qt5.The functional modules include communication module,online upgrade module programming,and data display module.Then,the first wave arrival extraction algorithm commonly used in engineering is studied and the STA/LTA algorithm was implemented to verify the algorithm of CBUILT.At the end of the thesis,the key functions of the detection system were tested,using the detection system to verify the communication functions,online upgrades,data acquisition and other functions of the CBUILT;and the transducer was subjected to high temperature experiments.By analyzing and comparing the experimental results,it is proved that the detection system can complete the design requirements.