Research and Application of Magnetic Flux Leakage Internal Detection Technology for Small-Diameter Pipelines in Huabei Oilfield

Abstract Small caliber pipelines in Huabei Oilfield are widely distributed and transport complex media. In the complex geographical environment, they face various potential risks and challenges, such as the occurrence of defects such as corrosion, cracks, deformation, and the influence of external environment. The utilization of magnetic flux leakage (MFL) for internal defect screening represents a mainstream approach in non-invasive testing methodologies, which detects defects by detecting changes in the magnetic field inside the pipeline. This investigation presents a methodological breakdown of MFL technology’s fundamental operational principles in internal defect assessment. Through multi-axis magnetic field vector analysis, this advanced MFL methodology achieves optimized defect detection efficiency in automated pipeline integrity assessments, Tailored to the flow assurance challenges inherent in Huabei’s aging small-bore (DN80-DN150) pipeline clusters, a small-diameter pipeline is selected for internal detection application. Through data analysis and excavation verification of the detection results, Field implementations in refinery piping systems validate the triaxial MFL platform’s dual-capability in corrosion mapping and weld defect sizing, and it provides a practical reference for more extensive internal pipeline detection applications in Huabei Oilfield in the future.