油管接触应力超声信号试验研究

Experimental Study on Contact Stress Ultrasonic Signal of Tubing

为了定量评价油套管接头连接的密封质量,借助金属接触试验装置对油管常用L80-13Cr材料试样进行试验,对超声回波信号进行S变换降噪后的时频域分析,提取不同接触压力下的信号时域及频域特征进行了定量分析。分析结果表明:经过S变换降噪后的超声时域、频域信号图可以直观地显示油管粗糙接触面的时域及频域特征;回波时域峰值与接触压力指数相关,一次回波时域峰值可作为评价油管接触面所受应力的特征参数;超声回波信号频域峰值和接触压力呈负线性相关。研究结果可为评价油管接头密封性提供理论及数据支撑。

To quantitatively evaluate the sealing quality of the connection of the tubing and casing joint,the metal contact test device is used to test the L80-13Cr material sample commonly used in the tubing.The time-frequency domain analysis of the ultrasonic echo signal after S-transform noise reduction is performed to extract signal time-and frequency-domain characteristics under contact pressure to conduct quantitative analysis.The analysis results show that the ultrasonic time-domain and frequency-domain signal diagrams after S-transform noise reduction can intuitively display the time-domain and frequency-domain characteristics of the rough contact surface of the tubing.The time-domain peak value of the echo is exponentially related to the contact pressure.The time-domain peak value of the primary echo can be used as a characteristic parameter to evaluate the stress on the contact surface of the tubing.The peak of the frequency-domain of the ultrasonic echo signal is negatively linearly related to the contact pressure.The study can provide theoretical and data support for evaluating the sealing of tubing joints.