固井水泥环内部缺陷超声波检测仿真研究

Simulation Study on Ultrasonic Testing of Defects in Cement Sheath

固井水泥环内部的各种缺陷会导致层间窜流、井口带压等事故。无损检测技术作为一种非破坏性的检测方法,可以对固井水泥环内部的缺陷进行检测。基于超声波在连续介质中的传播规律,采用COMSOL仿真软件模拟压电效应以及超声波在水泥环中的传播状态和反射规律,研究水泥环缺陷反射信号的相关特性。研究结果表明:选择1.0 MHz 5周期Hanning窗调制的超声正弦波作为激励信号,超声探头可以在50μs内接收到水泥环缺陷的反射信号;不同类型的缺陷中,矩形缺陷的检测效果最佳;当缺陷主方向与超声波入射方向垂直时,检测效果最佳。研究结果验证了超声波无损检测技术可以快速准确地确定固井水泥环内部缺陷的类型和位置,同时调整超声波入射角度有助于提升检测效果,可为超声波在水泥环内部缺陷检测中的应用提供一定的指导意义。

Various defects in cement sheath may lead to accidents such as interlayer cross flow and wellhead under pressure.Nondestructive testing(NDT)is a technology that can detect the defects in the cement sheath.Based on the propagation pattern of ultrasonic waves in continuous media,the COMSOL simulation software was used to simulate the piezoelectric effect and the propagation state and reflection law of ultrasonic waves in cement sheath,and identify the relevant characteristics of reflected signals of defects in the cement sheath.The results show that when a 1.0 MHz 5-period Hanning window modulated ultrasonic sine wave is selected as the excitation signal,the ultrasonic probe can receive the reflected signal of cement sheath defects within 50μs.Among different types of defects,the rectangular defects have the best detection effect.When the principal direction of the defect is perpendicular to the direction of ultrasonic incidence,the detection effect is the optimal.The ultrasonic NDT technology can quickly and accurately determine the type and location of defects in the cement sheath.Meanwhile,adjusting the angle of ultrasonic incidence can help improve the detection effect.The study results provide certain guidance for the application of ultrasonic wave in the detection of defects in cement sheath.