Optical fiber sensors for oil well temperature and pressure measurement

ExtrinsicFabry-Perot interferometer (EFPI) based optical fiber sensors are designed for temperature and pressure sensing in oil well. To minimize the cross-sensitivity between temperature and pressure, several practical methods have been developed for the sensors: using a pressure isolated and good heat conductive package design can very well shield the impaction of pressure variation for a temperature sensor, and using the same fused silica material for both reflected fiber and collimated capillary, and improving the F-P cavity bonding structure can effectively self-compensate and reduce the temperature dependence of a pressure sensor Experimental results show that an accuracy of 0.5% FS for both the temperature and pressure sensors has been achieved.