Fiber optic Fabry–Perot pressure sensor with low sensitivity to temperature changes for downhole application

• Published in: Optics communications Vol. 269; no. 2; pp. 322 - 330
• Main Authors: Aref, S.H., Latifi, H., Zibaii, M.I., Afshari, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-01-2007; Elsevier Science
• Subjects: Applied sciences; Circuit properties; Downhole instrumentation; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Extrinsic fiber Fabry–Perot interferometer; Fiber Bragg grating; Fiber optic sensor; Fundamental areas of phenomenology (including applications); General equipment and techniques; Gratings; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Integrated optics. Optical fibers and wave guides; Optical and optoelectronic circuits; Optical elements, devices, and systems; Optics; Physics; Pressure; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Temperature cross-sensitivity; Fiber Bragg grating; Temperature cross-sensitivity; Extrinsic fiber Fabry–Perot interferometer; Pressure; Fiber optic sensor; Downhole instrumentation; Pressure sensors; Extrinsic fiber Fabry-Perot interferometer; Instrumentation; Diffraction gratings; Grating in fiber; Fiber optic sensors; Bragg gratings; Pressure measurement; Fabry-Perot interferometers
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2006.08.009

Pressure and temperature are two important parameters in reservoir engineering. The fiber optic sensors can be used for permanent downhole monitoring. In this paper, we propose an extrinsic fiber Fabry–Perot interferometer (EFPI) sensor for pressure measurement with low sensitivity variation. The pressure sensitivity of EFPI sensor and of the fiber Bragg grating (FBG) sensors have been measured. The experimental pressure sensitivity for EFPI and FBG sensors are measured to be 2.75×10−81/kPa and 1.52×10−81/kPa, respectively. The temperature cross-sensitivity problem of the EFPI sensor has been solved by a new technique. The temperature sensitivity of EFPI sensor has been decreased to 1.2×10−6/°C, while the temperature sensitivity of non-compensated EFPI sensor has been measured to be 16.4×10−6/°C. The results show that the EFPI sensor has a higher pressure sensitivity and good capability to decrease temperature sensitivity in comparison to FBG sensor.