Abstract
Because of their low flexibility, traditional vibration sensors cannot perform arbitrary bending adjustments when facing curved surfaces and other complex working conditions during the drilling process; therefore, this research proposes a ring-shaped vibration sensor (RSV−TENG) that can deform freely in the bending direction, and which can be used in working conditions where the inner bending angle of the drill pipe changes greatly. Test results show that the vibration frequency measurement range is from 4 Hz to 16 Hz, with a measurement error less than 4%, the vibration amplitude measurement range is less than 20 mm, with a measurement error less than 5%, the output voltage and current signal are 120 V and 60 nA, respectively, when three RSV−TENGs are connected in parallel, and the maximum output power is 6 × 10−7 W when the external resistance is 106 Ω. Compared with traditional downhole sensors, this sensor has self-powered and self-sensing functions, eliminating the shortcomings of battery and cable power supply; in addition, this sensor can be installed in the drill pipe space with different curvature radii, so it is more suited to complex and changeable downhole working conditions.