Preparation and Characterization of a Biobased Temporary Plugging Material: Self-Healing and Degradable

Due to the low success rate in high-temperature gas well drilling or workover operations, a new type of biobased temporary sealing material was synthesized using vanillin, succinic anhydride (SA), cellulose, and acetylacetone zinc hydrate (AZH) as catalysts. Infrared analysis proved the synthesis of vanillin-derived epoxy and the formation of a vitrimer with hydroxyl ester. The results of thermodynamic properties tests show that it has excellent thermal stability with a high glass transition temperature (T_g). The dynamic mechanical test results show that the characteristic relaxation time of the material at 120 °C is 3500 s and the self-healing rate can reach 61% within 20 min. The test results of mechanical properties show that under 10 MPa pressure, it has good elastic deformation performance, the rebound rate is more than 36%, and the crushing rate is less than 17%. The degradation performance results show that the decomposition increases to 80% under 120 °C and 1.2% NaOH. The comprehensive performance evaluation results show that the new temporary plugging material has good compatibility, and its plugging performance is better than those of a gel, composite material, and shape memory polymer. The maximum fracture plugging capacity is 5 × 4 mm, with a pressure up to 10 MPa.