Small-sized temperature and pressure sensors based on fiber bragg grating for oil and gas wells

This paper presents a novel temperature and pressure sensor with a small volume and large range, which can measure the temperature and pressure accurately in oil and gas wells. The feasibility of the sensor is verified by theoretical calculation and simulation, and the relationship between the sensor structure and the wavelength of fiber Bragg grating is established. The structure of the sensor is optimized by simulation, so that the sensor has good performance. The performance of the sensor is verified by experiments, which can measure temperature and pressure independently, the pressure range of the sensor is 0–40 MPa, the sensitivity is 24.05 pm/MPa, the linearity is 0.9997, and the repeatability is 0.0038. The temperature measurement range is 25–200 ℃ and the sensitivity is 31.16 pm/℃. The sensor is packaged with solid glass particles and it can operate for long periods in high temperature environments.