A Calculation Method of Pipeline Bending Strain Based on IMU Data of Pipeline Internal Detection

Abstract In the process of service, long-distance oil and gas pipelines are located in a complex and changing environment, and the pipelines are prone to bending and deformation under the action of various factors, and in serious cases, wall rupture will occur, which will lead to major pipeline failure accidents. Therefore, accurately calculating the bending strain of the pipeline allows us to grasp the actual bending state of the pipeline, thus maximizing the prevention of pipeline failure due to bending deformation. In this paper, a method for calculating pipeline bending strain based on the attitude angle data of inertial measurement unit is proposed and verified with the inspection data of a pipeline. The results show that the proposed method has a certain degree of practicality and can effectively distinguish between structures such as bending deformation, elbows and bends. When there are bending deformations, elbows or bends in the pipeline, the calculated bending strains of the pipeline can be divided into three parts, including the transition section that gradually increases in the upstream, the transition section that gradually decreases in the downstream and the intermediate section that tends to be stabilized. However, when the structure for the elbow or bend and other structures, its bending strain calculation results relative to the bending deformation, with smaller fluctuations, the transition section is also more stable, and has a better symmetry, so that the elbow, bend and bending deformation can be effectively distinguished.