Research And Implementation Of Three-dimensional Ultrasonic Scanning Imaging Logging Experimental Device

In the exploration and development of petroleum,ultrasonic imaging logging has been widely used due to its unique advantages such as intuitive images,full borehole coverage,wide application range,and convenient operation.Major logging companies continue to upgrade the instruments they have developed,by downgrading the probe frequency,improving the quantification accuracy,and striving to overcome the influence of downhole factors such as borehole size,mud attenuation,and surface structure of the borehole medium to improve image resolution.With the rapid development of exploration and production technology,higher requirements have been put forward for the refinement of ultrasonic imaging logging technology and the identification of small fractures.However,due to the complex logging environment and the non-ideal sound spots of the ultrasonic transducer,the logging images are blurred,which affects the analysis and interpretation of the characteristics of small geological bodies.Based on this trend,in order to improve ultrasonic imaging technology and ultrasonic logging image enhancement and restoration algorithms,it is necessary to combine ultrasonic excitation acquisition circuits and real-time imaging devices to carry out research on ultrasonic logging image degradation factors.To this end,this thesis launched the research on the 3D ultrasonic scanning imaging logging experimental device.The experimental device mainly includes a stepping motor control platform,an FPGA main control module,an acoustic wave excitation acquisition module and an upper computer imaging software,and is aimed at the key issues of each module.The corresponding design plan is proposed.The research work of this article mainly includes:1.The overall design scheme of the three-dimensional scanning platform and the acoustic wave excitation acquisition circuit is given.The experimental device uses FPGA as the control core.The function is to receive instructions from the upper computer through the received instructions,and perform functions of platform retracking and automatic scanning.In the automatic scanning function,the drive motor and sound waves excite the acquisition circuit to perform automatic acoustic scanning and imaging of different height planes in the set three-dimensional space.Test the imaging effect of different transmission media and different distances,and analyze the corresponding circuit gain curve.2.Designed the ultrasonic excitation acquisition hardware circuit.The transmitting circuit is composed of a PWM boost circuit module and a gating circuit module;the acquisition circuit includes a front-end signal conditioning circuit,a peak hold circuit,a first wave discrimination circuit and an AD acquisition circuit.The peak hold circuit and the first wave discriminating circuit are used to extract the first wave sound amplitude and arrival time of the echo to realize the amplitude imaging and time imaging of the experimental device.3.The upper computer control imaging software is designed,which is responsible for the control platform of the experimental device and the acquisition of data imaging.The main interface is designed with serial port,working mode,motor control,sonic excitation and sonic sampling parameter configuration controls.The operation control class is responsible for ordering down to the FPGA and suspending the working state of the platform.The imaging interface settings include original data image preservation and image enhancement algorithm entry,etc.The research work in this paper verifies the design scheme of the three-dimensional ultrasonic scanning imaging logging experimental device,which has a good guiding significance for the future research and development of the ultrasonic imaging experimental device with high integration,high precision,high performance and high dynamic receiving range.