Optimal Design and Experimental Study of the Receiver Sonde in Multipole Acoustic LWD Tools

The receiver sonde of multipole acoustic logging while drilling (LWD) tools directly affects the quality of collected signals and the stability of the tool’s mechanical structure. Therefore, the receiver sonde of multipole acoustic LWD tools was optimized in this study by combining finite element method and experimental measurements. The analysis of the receiver sonde simulation showed that the performance of the receiver sonde was mainly affected by the thickness and area of piezoelectric ceramic slices as well as the thickness and surface flatness of packaging shells. In addition, receiving sensitivity would be enhanced as the thickness of piezoelectric ceramic slices increased, and the area of piezoelectric ceramic slices had no obvious effect on receiving sensitivity when the frequency was below 15 kHz. Furthermore, the variation range of the receiving sensitivity would be smaller as the thickness of packaging shells decreased and the surface flatness increased. On this basis, long square tubes with aluminum shells were processed using 3D printing technology, with a thickness of 0.5 mm and 2.0 mm, respectively. Then, the fabricated receiver sonde was tested in terms of sensitivity, and the test results were in good agreement with the calculated results. As a result, it was demonstrated that thin-wall shells were more beneficial to the signal receiving of measurement. The optimal design of receiver sonde in multipole acoustic LWD tools will provide new possibilities for designing and developing acoustic LWD tools in China.