Optimization and Field Performance Evaluation of a Novel Magnetic Tracer Slurry for Sealing Gas Extraction Boreholes

ABSTRACT This study presents a comprehensive evaluation and optimization methodology for a novel magneticv tracer sealant, integrating physical experiments and response surface methodology (RSM) to assess its rheological properties and particle suspension behavior. The experimental findings indicate that the water-cement ratio exerts the most substantial influence on the rheological properties. To address the limitations of single-component tracers, a novel micron–nano composite magnetic particles system was developed. The synergistic effect of nanoparticle mass fraction and water-cement ratio was systematically optimized using RSM. The results show that when the material ratio is 0.95:1, the mass fraction of magnetic particles is 13.41 %, and the nanoparticle mass fraction is 14.04 %. The slurry prepared with this optimized formula exhibited outstanding performance, demonstrating excellent fluidity and suspension stability. This study provides a novel technical solution and a robust methodological reference for developing and assessing functional grouting materials in underground engineering.