Regenerative Granular Hydrogels With Controlled On‐Demand Dissolution as Temporary Mechanical Barriers

ABSTRACT Granular hydrogels with excellent injectability, thermal stability, and mechanical robustness have shown promise in applications such as drilling, hydraulic fracturing, and profile control. However, most existing granular hydrogels lack a combination of key functionalities—namely, re‐crosslinkability, mechanical robustness, and controlled dissolution—needed for subsurface energy engineering. Herein, we report the development of ionically regenerative granular hydrogels that can reassemble into strong bulk hydrogels, exhibit self‐growth upon the addition of new granules, and undergo on‐demand hydrolysis into water‐like fluids. The reconstructed bulk hydrogels demonstrate mechanical robustness comparable to their pristine counterparts. The re‐crosslinking process is synergistically regulated by salinity and temperature, enabling targeted fracture sealing. Introducing environmentally benign breakers, such as carbonate salts, to the reformed hydrogels yields low‐viscosity solutions similar to water. Furthermore, the choice of breaker dictates the hydrolysis kinetics, allowing for complete dissolution within tens of minutes. Petrophysical evaluations confirm the hydrogels' ability to reform, resist mechanical degradation under differential pressure, and fully dissolve when triggered. Overall, we demonstrate regenerative granular hydrogels that integrate re‐crosslinkability, self‐growth, mechanical durability, and tunable hydrolysis—making them well‐suited for advanced fracture treatment in petroleum engineering.