基于超声波合成孔径技术的钻孔成像方法

随着地下空间开发的深入，钻孔岩壁上特殊区域的重视程度越来越高，为了克服传统超声波钻孔成像技术分辨率低的不足，提出一种基于超声波合成孔径技术的钻孔成像方法，提高钻孔图像的分辨率和图像质量。采用高分辨率的合成孔径SAFT成像技术综合处理大量的断面扫描回波信号，达到增强反射信号和抑制干扰信号的目的，使对应的岩壁特征区域回波更加突显，在该基础上提取出扫描断面回波信号的声幅和声时参数。综合声幅和声速参数的特征，提出了基于相关性的超声波钻孔图像重建原则，选择合适的成像数据点，在叠加不同深度的探测数据后形成了关注区域更加明显的钻孔重建图像。将该方法应用到了实际工程中，验证了该方法的可行性和准确性。

Borehole imaging method based on ultrasonic synthetic aperture technology

With the development of underground space, more and more attention has been paid to the special areas on borehole wall. In order to overcome the low resolution of traditional ultrasonic borehole imaging technology, a new borehole imaging method based on ultrasonic synthetic aperture technology is proposed to improve the resolution and image quality. Firstly, high resolution synthetic aperture focusing technique(SAFT) is used to synthetically process a large number of cross-section scanning echo signals, so as to enhance the reflection signal and suppress the interference signal, which makes the echo of the corresponding typical area at the rock wall more prominent. Then the sound amplitude and sound time parameters of the scanned cross-section echo signals are extracted. The principle of ultrasonic drilling image reconstruction based on correlation is proposed based on the synthesized characteristics of sound amplitude and sound velocity parameters. After superimposing the detection data of different depths, the borehole reconstruction image with more obvious focus area is formed. Finally, the method is applied in practical engineering, and its feasibility and accuracy has been verified.