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Fiber Bragg Grating Sensors for the Oil Industry

View Article: PubMed Central - PubMed

ABSTRACT

With the oil and gas industry growing rapidly, increasing the yield and profit require advances in technology for cost-effective production in key areas of reservoir exploration and in oil-well production-management. In this paper we review our group’s research into fiber Bragg gratings (FBGs) and their applications in the oil industry, especially in the well-logging field. FBG sensors used for seismic exploration in the oil and gas industry need to be capable of measuring multiple physical parameters such as temperature, pressure, and acoustic waves in a hostile environment. This application requires that the FBG sensors display high sensitivity over the broad vibration frequency range of 5 Hz to 2.5 kHz, which contains the important geological information. We report the incorporation of mechanical transducers in the FBG sensors to enable enhance the sensors’ amplitude and frequency response. Whenever the FBG sensors are working within a well, they must withstand high temperatures and high pressures, up to 175 °C and 40 Mpa or more. We use femtosecond laser side-illumination to ensure that the FBGs themselves have the high temperature resistance up to 1100 °C. Using FBG sensors combined with suitable metal transducers, we have experimentally realized high- temperature and pressure measurements up to 400 °C and 100 Mpa. We introduce a novel technology of ultrasonic imaging of seismic physical models using FBG sensors, which is superior to conventional seismic exploration methods. Compared with piezoelectric transducers, FBG ultrasonic sensors demonstrate superior sensitivity, more compact structure, improved spatial resolution, high stability and immunity to electromagnetic interference (EMI). In the last section, we present a case study of a well-logging field to demonstrate the utility of FBG sensors in the oil and gas industry.

No MeSH data available.


Schematic diagram of FBG pressure sensor.
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sensors-17-00429-f009: Schematic diagram of FBG pressure sensor.

Mentions: Previously, we fabricated, the robust and highly sensitive pressure sensor shown in Figure 9. A FBG is attached to the surface of a cantilever beam sealed into a metal box or sheath. A small bellows, which replaces part of the wall of the box, is connected to the free end of the beam. The oil and gas down the well applies pressure on the bellows and consequently deforms the beam. The attached FBG is stretched with the bending of the beam. The method effectively protects the FBG by preventing the oil and gas coming in direct contact with the FBG, as well as improving the FBG’s low intrinsic response to the pressure. Besides, the cast-iron sheath helps the FBG to withstand the high pressure up to 100 Mpa.


Fiber Bragg Grating Sensors for the Oil Industry
Schematic diagram of FBG pressure sensor.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5375715&req=5

sensors-17-00429-f009: Schematic diagram of FBG pressure sensor.
Mentions: Previously, we fabricated, the robust and highly sensitive pressure sensor shown in Figure 9. A FBG is attached to the surface of a cantilever beam sealed into a metal box or sheath. A small bellows, which replaces part of the wall of the box, is connected to the free end of the beam. The oil and gas down the well applies pressure on the bellows and consequently deforms the beam. The attached FBG is stretched with the bending of the beam. The method effectively protects the FBG by preventing the oil and gas coming in direct contact with the FBG, as well as improving the FBG’s low intrinsic response to the pressure. Besides, the cast-iron sheath helps the FBG to withstand the high pressure up to 100 Mpa.

View Article: PubMed Central - PubMed

ABSTRACT

With the oil and gas industry growing rapidly, increasing the yield and profit require advances in technology for cost-effective production in key areas of reservoir exploration and in oil-well production-management. In this paper we review our group’s research into fiber Bragg gratings (FBGs) and their applications in the oil industry, especially in the well-logging field. FBG sensors used for seismic exploration in the oil and gas industry need to be capable of measuring multiple physical parameters such as temperature, pressure, and acoustic waves in a hostile environment. This application requires that the FBG sensors display high sensitivity over the broad vibration frequency range of 5 Hz to 2.5 kHz, which contains the important geological information. We report the incorporation of mechanical transducers in the FBG sensors to enable enhance the sensors’ amplitude and frequency response. Whenever the FBG sensors are working within a well, they must withstand high temperatures and high pressures, up to 175 °C and 40 Mpa or more. We use femtosecond laser side-illumination to ensure that the FBGs themselves have the high temperature resistance up to 1100 °C. Using FBG sensors combined with suitable metal transducers, we have experimentally realized high- temperature and pressure measurements up to 400 °C and 100 Mpa. We introduce a novel technology of ultrasonic imaging of seismic physical models using FBG sensors, which is superior to conventional seismic exploration methods. Compared with piezoelectric transducers, FBG ultrasonic sensors demonstrate superior sensitivity, more compact structure, improved spatial resolution, high stability and immunity to electromagnetic interference (EMI). In the last section, we present a case study of a well-logging field to demonstrate the utility of FBG sensors in the oil and gas industry.

No MeSH data available.