Fiber Optic Pressure / Temperature Gauge
Principle of Fabry Perot cavity fiber optic pressure gauge technology
The Fabry Perot cavity sensor is based on the principle of optical interference, and its core structure is a small cavity composed of two highly parallel reflecting surfaces.
▪ When external pressure or temperature changes, the length of the cavity will undergo extremely small changes, resulting in correspond- ing shifts in the interference fringes of the reflect-ed light signal.
▪ Through high-precision spectral demodulation technology, interference signals can be converted into precise values of pressure and temperature, achieving high-precision downhole measure-
ments.
Compared with traditional strain gauges or electronic sensors, Fabry Perot cavity fiber optic sensors require no power supply, are resistant to electromagnetic interference, corrosion-resistant, and high-temperature, making them particularly suitable for complex environments in oil and gas wells.
Optimization of underground instrument packag- ing and high temperature stability
The long-term stability of fiber optic Pressure Temp gauge depends on sensor packaging technology and structural design.
▪ After years of optimization, the packaging
materials and structure of the system have been greatly improved, using high-temperature alloy materials and fully sealed packaging technology to greatly suppress long-term drift problems.
▪ In high-temperature underground environ- ments of 150 °C and 300°C, the instrument can still maintain extremely low zero drift, achieving long-term accurate monitoring.
▪ The permanent installation and application of this instrument in Tuha Oilfield has achieved a
continuous operating life of more than 5 years, far superior to traditional electronic pressure
thermometers, proving its excellent high-tempera- ture stability.
Typical application scenarios
▪ This fiber optic downhole pressure and
temperature monitoring system can be widely applied to:
▪ Long term monitoring of oil well pressure and temperature
(Conventional oil wells, gas wells, injection wells)
▪ Ultra deep and high-temperature wells
(Suitable for environments of 150 ° C and above)
▪ Steam assisted heavy oil extraction well (Applicable to SAGD and CSS processes)
▪ Dynamic monitoring of oil and gas reservoirs (Realtime monitoring of formation pressure and temperature changes, optimizing mining strate- gies)
▪ Integrity assessment of wellbore
(Analyzing wellbore status through abnormal pressure to prevent underground accidents)
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