DI-UMONS : Dépôt institutionnel de l’université de Mons

Recherche transversale
(titres de publication, de périodique et noms de colloque inclus)
2019-02-15 - Travail avec promoteur/Doctorat - Anglais - 151 page(s)

Huang Ji-Ying, "Development of Fiber Bragg Grating Sensor Written in Specialty Fiber for High Temperature and High Pressure Monitoring", Caucheteur Christophe (p) , Bette Sébastien , soutenue le 2019-02-15

  • Codes CREF : Capteurs et périphériques (DI2563), Optique des fibres (électromagnétisme) (DI1252)
  • Jury : Mégret Patrice (p) , Wuilpart Marc , Geernaert Thomas, Jan Van Roosbroeck, Missinne Jeroen
  • Unités de recherche UMONS : Electromagnétisme et Télécommunications (F108)
  • Instituts UMONS : Institut de Recherche en Science et Ingénierie des Matériaux (Matériaux)
  • Centres UMONS : Ingénierie des matériaux (CRIM)

Abstract(s) :

(Anglais) In this PhD thesis, the pressure and temperature monitoring is accomplished with a fibre Bragg grating (FBG) written by a femtosecond laser pulse in the so-called Butterfly micro-structured fiber (MSF). To begin with, we first optimized the fiber handling procedure for the Butterfly MSF. In the step of FBG inscription in the Butterfly MSF, we then optimized the laser inscription parameters when inscribing in standard single-mode fiber (SMF) due to its simple cross-section structure as a comparison to the Butterfly MSF. In the end, the inscription laser power was selected to have acceptable grating stability at elevated temperature and to have low birefringent grating. We have studied the sensing ability of our MS-FBG sensor by presenting different characterization results both on purely fiber level and with sensor packaging. The main purpose of this characterization was to mimic the working conditions in downhole environments including the sensor sensitivity to temperature and to pressure, temperature and pressure stability and the induced pressure error in a rapid temperature transient, etc. To improve the FBG stability at elevated temperature, we empirically obtained a suitable accelerated aging recipe and can offer a great stability with less than 0.3°C in temperature variation and with less than 0.42 bar in pressure variation over 7 days at 280°C. We also developped a dedicated packaging. Our sensor packaging not only offers a mechanical protection to the fiber but also transfers the well pressure into its sensing element. Packaged MS-FBG sensor was also validated in a laboratory environment first before deploying in the field. Results are in good agreement to the results obtained on the fiber level. Finally, the packaged MS-FBG sensor was brought to the field and was verified in a test well before a real deployment