A FBG Hoop-strain Sensor For Monitoring The Uniform Corrosion Of Pipeline

With the developing of the oil and gas pipeline, coverage is more widely and the climatic conditions are more complex. Therefore the monitoring sensor is needed to satisfy more requirements. Given to the requirements of oil and gas pipeline serving, the characteristics of pipeline corrosion and the advantages of the FBG sensor, a new long oil and gas pipeline monitoring method, which is based on the FBG hoop-strain sensor, is proposed.In the first chapter, the pipeline developing conditions in our country and the problems occurs our country are introduced, in addition, the existing monitoring methods for oil and gas pipeline are discussed. Compared with the others, the FBG sensing technique has the advantages such as resistance to acid and alkali corrosion, anti-electromagnetic interference, high measuring accuracy and small side. This part introduces the basic principle and the applying conditions of the FBG sensing technique.The second chapter describes the encapsulation technique and the installation method for the FBG hoop-strain sensor, and introduces the principle for applying the FBG hoop-strain sensor to pipeline monitoring. In order to discuss the characteristic of the FBG hoop-strain sensor pressure calibration test, the load cycling test and the recycling test are conducted and the results demonstrate that the FBG hoop-strain sensor has the excellent linear characteristic, the stable work performance and the recycling.In the third chapter, in order to study the applicability for applying the FBG hoop-stain sensor to the cross pipeline corrosion, thickness calibration test are discussed, in which different thicknesses represent different corrosion degrees. The results demonstrate that the FBG hoop-strain sensor is sensitive to the thickness variation and identify different corrosion conditions.In the fourth chapter, the applicability for applying the FBG hoop-strain sensor to the pipeline local corrosion is discussed. The results demonstrate that the FBG hoop-strain sensor is sensitive to the local corrosion.