Phased array ultrasonic testing method for drilling tool threads

Petroleum drilling tools play an important role in oil and gas extraction and are subjected to alternating loads for a long time. However, due to their much smaller structural stiffness compared with the drilling tool itself, the threads of the drilling tools are prone to fatigue failure. To overcome the problem of the low detection ability of conventional ultrasound for root cracks in drilling tool threads, this paper proposes a new ultrasonic detection method for drilling tool threads based on phased array ultrasound. A finite element numerical calculation model for ultrasonic testing of drilling tool threads is established, and the detection capabilities of fan-shaped scanning phased array ultrasound and fully focused phased array ultrasound for root cracks of drilling tool threads are studied through numerical simulation. The detection parameters are optimized, and the detection results of the two phased array ultrasonic testing methods are compared. Finally, the effectiveness of the proposed method is verified through experiments.