Synthesis and properties of PAM / PLA composite degradable particle temporary plugging agent

Abstract Using acrylamide (AM) and polylactic acid (PLA) as raw materials, polyacrylamide (PAM)/PLA composite temporary plugging agent TZDJ (TZDJ is a synthetic self‐degrading stopper) was synthesized by inverse suspension polymerization. The chemical structure, chemical composition, microscopic morphology, and thermal stability of TZDJ were characterized by Fourier infrared spectral analysis (FT‐IR), carbon nuclear magnetic resonance spectroscopy (13C NMR), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The degradation and plugging properties of TZDJ were studied by laboratory experiments, and the self‐degradation mechanism of TZDJ was proposed. The results show that TZDJ has good temperature and salt resistance, and it is completely degraded by hydrolysis at 180°C for 120 h. The fracture core displacement experiment shows that TZDJ has good plugging and core permeability recovery performance, and its temporary plugging rate and core permeability recovery rate are all above 90%. The FT‐IR and SEM analysis showed that the degradation process of TZDJ was divided into three stages: degradation of shell PAM, core PLA, and degradation product small molecules.