Systems and methods for monitoring temperature using a magnetostrictive probe

Abstract

Systems and methods for monitoring temperature distribution in downhole equipment using magnetostrictive probes. In one embodiment, an ESP motor has a stator with a rotor and shaft rotatably positioned within the stator. Magnetostrictive sensors are positioned within the motor. Each magnetostrictive sensor has a transducer, a probe, and electronic circuitry coupled to the transducer. The circuitry generates an initial electrical signal that is conveyed to the transducer. The signal passes through one or more coils in the transducer, generating magnetic fields that induce an acoustic signal in the probe. The acoustic signal propagates through the probe and waves are reflected from reflection points in the probe. The transducer senses the reflected acoustic waves and provides corresponding electrical signals to the circuitry, which determines timing intervals associated with the reflected waves and uses this information to determine temperatures at one or more locations in the probe (hence in the monitored equipment).