Research on the Weak Magnetic Stress External Detection Technology for Buried Gas Pipelines

Abstract

The long - term stress damage caused by working load and additional load seriously affects the safe operation of the pipeline. Aimed at the stress detection of buried gas pipelines, the research was carried out on the pipeline weak magnetic stress external detection technology. By establishing the equivalent magnetic dipole model of the pipeline stress concentration zone, the numerical simulation of the normal component By and the tangential component Bx was carried out using Matlab software, and the distribution characteristics of the magnetic field components in stress concentration zone were obtained. A weak magnetic stress external detection on the Nanqi line 2 km gas pipeline under Changqing Oilfield combined with the magnetic field distribution characteristics of the stress concentration area obtained from the above - mentioned simulation analysis, 6 medium - risk stress damages and 14 low - risk stress damages were detected. The contact metal magnetic memory (MMM) detector was used to conduct excavation detection on two selected feature points. The MMM detection results of the two excavated pits were consistent with the pipeline weak magnetic stress external detection results. Results showed that the pipeline weak magnetic stress external detection technology was a new technology that could effectively detect pipeline stress damages, predict pipeline hazards and thus played an important role in assisting the safety management of pipelines.

Keywords

• buried gas pipeline|stress damage|magnetic dipole|external detection|safety management