Preformed particle gels (PPGs) have been broadly used in temporary plugging steering fracturing techniques. However, it is difficult to achieve both excellent mechanical and degradable properties in conventional PPGs. To address this issue, double crosslinked self-degradable preformed particulate gels (DCSPPGs) were prepared using starch, hydroxyethyl acrylate, and acrylamide, crosslinked with poly (ethylene glycol) diacrylate (PEGDA) and borax. The structure was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), confirming the successful preparation of DCSPPGs. The mechanical properties of DCSPPGs indicate that the elastic modulus of DCSPPGs reached 22 918 Pa, which is much higher than that of most similar particle gels. Meanwhile, DCSPPGs can be degraded to a low-viscosity liquid within 36 hours without any visible solid residues. It shows that DCSPPGs have excellent mechanical and degradation properties. In addition, this study systematically evaluated the effects of particle size, temperature, and monovalent (Na+) vs. divalent (Mg2+ and Ca2+) ions on the swelling and degradation properties of the DCSPPGs. These findings reveal that DCSPPGs maintain exceptional degradation performance in high-temperature (150°C) and high-salinity (30% NaCl) environments. Core displacement experiments showed that the maximum breakthrough pressure of the core after DCSPPGs sealing could reach 27.69 MPa and that the permeability injury rate of the core after degradation was only 3.55%. It shows that DCSPPGs have excellent sealing performance and minimal formation damage post-degradation.

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