Technologies and application of pipeline centerline and bending strain of In-line inspection based on inertial navigation

Inertial mapping unit (IMU) in-line inspection (ILI) has become routine practice for long-distance buried transport pipelines of oil and gas. It is capable of measuring the pipeline centerline position coordinates and locating the pipeline anomalies, features and fittings to help the oil company manage it. The IMU inspection data also can be used to compute the pipeline bending strain and assess the potential deviation from the original position where endures the extra stress. This paper introduces the main principle, measurement and data processing for IMU ILI. As a key point of calculation for centerline and bending strain, the identification and optimization of the signal are also discussed. At the end of this paper, the developments of IMU ILI are presented. The IMU ILI becomes an important and effective method for pipeline integrity management and safe operation of buried oil and gas pipelines.