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Indexed by:期刊论文

Date of Publication:2012-08-01

Journal:MEASUREMENT SCIENCE AND TECHNOLOGY

Included Journals:SCIE、EI、Scopus

Volume:23

Issue:8

ISSN No.:0957-0233

Key Words:Fabry-Perot interferometer; distributed temperature sensor; wavelength-division multiplexing; down-hole monitoring

Abstract:A cost-effective sensing system combining the fiber Fabry-Perot interferometer-based pressure sensor with the distributed temperature sensor is presented. This sensing system can realize accurate pressure measurement of the oil reservoir and temperature profile measurement of the wellbore simultaneously. For the sensing wave bands of the pressure and temperature sensor are different, the wavelength-division multiplexing (WDM) technology was used to couple the two sensing signals into one single fiber. As the wavelength difference between Stokes peak and anti-Stokes peak is larger than the bandwidth of commercial WDM, a wide bandwidth WDM with gain flattening range up to 80 nm was custom-made. Experimental results showed that this sensing system can reach 0.1% accuracy for the pressure measurement with a 0-30 MPa working range and 1 degrees C accuracy for the temperature measurement in a working range from room temperature to 300 degrees C. Additionally, a resolution of below 1.4 kPa for the pressure measurement and 0.5 degrees C for the temperature measurement had been realized. Field test results showed that this sensing system also has good long-term stability in high-temperature environment down hole.