石油钻井中超声相控阵井壁成像检测技术研究

Research on Ultrasonic Phased Array Imaging Testing Technology for Oil Borehole

针对石油钻井中井壁成像的现状,在对柱面线性相控阵(Cylindrical linear phased array,CLPA)换能器辐射声场研究的基础上进行换能器的参数优化和选择,设计并制作了一种基于CLPA换能器的井下超声相控阵井壁成像检测系统。该系统包括声系短节、电路短节和地面系统等,声系短节由CLPA换能器组成,避免了常规声系中探头绕井轴的机械旋转方式,电路短节由高集成度的发射接收模块和基于FPGA+DSP架构的数字信号处理模块组成,完成对井壁回波信号幅度和到时信息的提取,最终实现实时高效的井壁成像显示。利用该系统在试验井中对存在不同尺寸缺陷的套管进行现场测试,结果表明:该系统对套管井的成像结果能够反映缺陷的基本位置及尺寸等信息,具有良好的成像效果。

According to the current situation in borehole imaging,the parameter of the cylindrical linear phased array（CLPA） transducer is selected and optimized on the basis of simulation of acoustics radiation field of CLPA transducer.A down-hole system for borehole imaging based on CLPA transducer is designed and manufactured.The system includes an acoustics cartridge,a circuit cartridge and ground control system.The acoustics cartridge is composed by the CLPA transducer to avoid mechanical rotation of the probe as the traditional ultrasonic borehole imaging device.The circuit cartridge is composed by a transmitter receiver module in high level of integration and a digital signal processing module based on FPGA and DSP architecture,completing the magnitude and the time information extraction of echo signal of borehole wall,and ultimately displaying real-time borehole imaging.Scanning and imaging experiments are carried out in test wells for different size of defects using this system.It is shows that the basic location and size information of the defects can be reflected in the borehole imaging by the ultrasonic phased array system designed and the CLPA has a good imaging ability.