A strain and displacement inspection technology for oil/gas pipelines in earthquake areas

In this paper, a strain and displacement inspection method based on inertial navigation technology was proposed to inspect effectively the additional stress on oil/gas pipelines in earthquake areas. By means of this method, the whole oil/gas pipeline can be inspected effectively so that displacement and strain concentration points of oil/gas pipelines can be discovered in time. After pipeline is inspected by the inner-detector which carries the inertia measurement unit (IMU), combined with odometer and surface marker for navigation data fusion, its accurate centerline coordinates is obtained. Then, the bending strain of the pipeline is calculated. Thus, strain change and displacement areas along the whole pipeline can be identified effectively, and strain variation and displacement variation can be detected as well. The correctness of strain detection and the reproducibility of data are verified by means of traction test. This method provides the effective guarantee for the safe operation of long-distance oil/gas pipelines in earthquake areas.