Identification and evaluation on bending deformation of China-Russia Eastern Gas Pipeline

Local displacement and bending deformation of pipeline may occur under the action of external load. When superimposed with defects such as pipeline body corrosion, manufacturing or weld defects, the pipeline body will probably fail at the stress concentration point, seriously threatening the safety of personnel and causing environmental pollution and economic losses. In-line inspection technology based on inertial surveying and mapping is an effective method to accurately identify the bending deformation of pipelines and detect bending strain, which reflects the bending state of pipelines under external load in the form of bending strain during detection of the whole pipeline. The pipeline section of China-Russia Eastern Gas Pipeline within China starts from Heihe in the north and terminates at Shanghai in the south, passing through the geologically-unstable areas like marshes, freezing and thawing in alpine regions, where the movement of soil caused by natural disasters such as floods and earthquakes may also exert external load on the pipeline body. The pipeline body is likely to bend under the action of external force, and high-risk points are prone to be generated due to local stress concentration. By analyzing the bending strain data of the pipeline in combination with the pipeline defects found by geometric/leakage flux in-line inspection, the high-risk points that pose potential threats to the safe operation of the pipeline can be identified and located more accurately, and the monitoring and repair plans can be developed accordingly, so as to provide effective means for the safe operation of China-Russia Eastern Gas Pipeline.