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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.


Testing result of the glue, the sample with the particles of 4% nanometer SiO2 is the optimized one.
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sensors-17-00429-f018: Testing result of the glue, the sample with the particles of 4% nanometer SiO2 is the optimized one.

Mentions: In the above section, the temperature and strain measurement properties of FBGs have been discussed. For oil and gas fields, the naked FBGs are unable to measure the physical parameters in the harsh environments within wells. The gratings must be supported and protected by sturdy packaging techniques, with attention to the materials and sensing structures. The long-term stability and repeatability of sensors in the downhole applications are determined by the packaging techniques, with the exception of the performances of the FBGs themselves, as discussed above. Our group employs the alloy material of Nb-40 Ti-5.5 Al for FBG packaging. The benefits of the material are the small elastic modulus, erosion resistance to H+, Cl−, CO2, H2S under well, and especially the high temperature and high pressure resistances. The packaging structure of the sensor is fabricated using the alloy, after which, the FBG is fixed in the metal structure using customized specific glue of a silane coupling agent into which 4% by volume of fused SiO2 nanoparticles are mixed. The mixing ratio is controlled to optimize the properties of the glue. Compared with the polypropylene rubber adhesive, the custom glue can maintain long-term good stability over the temperature range of −20 °C to 400 °C. The corresponding testing results have been finished in the experiment, as shown in Figure 18.


Fiber Bragg Grating Sensors for the Oil Industry
Testing result of the glue, the sample with the particles of 4% nanometer SiO2 is the optimized one.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

sensors-17-00429-f018: Testing result of the glue, the sample with the particles of 4% nanometer SiO2 is the optimized one.
Mentions: In the above section, the temperature and strain measurement properties of FBGs have been discussed. For oil and gas fields, the naked FBGs are unable to measure the physical parameters in the harsh environments within wells. The gratings must be supported and protected by sturdy packaging techniques, with attention to the materials and sensing structures. The long-term stability and repeatability of sensors in the downhole applications are determined by the packaging techniques, with the exception of the performances of the FBGs themselves, as discussed above. Our group employs the alloy material of Nb-40 Ti-5.5 Al for FBG packaging. The benefits of the material are the small elastic modulus, erosion resistance to H+, Cl−, CO2, H2S under well, and especially the high temperature and high pressure resistances. The packaging structure of the sensor is fabricated using the alloy, after which, the FBG is fixed in the metal structure using customized specific glue of a silane coupling agent into which 4% by volume of fused SiO2 nanoparticles are mixed. The mixing ratio is controlled to optimize the properties of the glue. Compared with the polypropylene rubber adhesive, the custom glue can maintain long-term good stability over the temperature range of −20 °C to 400 °C. The corresponding testing results have been finished in the experiment, as shown in Figure 18.

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.