Research on the 3D Imaging Method for Ultrasound Phased Array forward-looking imaging in wellbores

This paper presents the fundamental principles of downhole ultrasonic phased array forward imaging and conducts experiments based on this model. To address the complexities of sound propagation paths, Fermat's principle is employed to calculate the phase delays for each array element. The focusing characteristics of the forward imaging transducer are tested and analyzed, and specific strategies for beam scanning and echo data acquisition are provided. After data collection, geometric mapping is used to localize the echo signals in spatial coordinates, and a distance-weighted (DW) interpolation method is applied to achieve three-dimensional reconstruction. Experimental results demonstrate that this method effectively captures the shape and surface details of the scanned objects, offering both theoretical and experimental support for the development of downhole three-dimensional forward imaging technology.