Scheme and Key Technology Research of Internal Defects Positioning of Oil andGas Pipelines

摘要

This paper presents the current internal defects positioning technology of pipeline, and deeply analyzes the characteristics of the main positioning methods, error causing mechanism and accumulative characteristics, and proposes a new combined positioning procedure, which applies INS (inertial navigation system) assisted by ground markers /weld /odometer to achieve the exact position of internal defects of oil and gas pipeline. INS is the core of positioning as a non-contact measurement. Its positioning manner is not affected by the internal environment of the pipeline and the error production and accumulation characteristics can be estimated; applying ground markers and weld signal, INS errors could be limited at a small range. This paper also develops a mathematical model of INS, establishes the INS/odometer navigation algorithms in accordance with positioning characteristics of the pipeline internal defects, and makes quantitative analysis on the algorithm errors of INS and the combination, which makes a useful exploration so as to reduce positioning errors and develops high accuracy of the positioning scheme.