Preparation and Characterization of Polymeric Ultra-Low-Density Proppants: Epoxy/Phenolic Resin-Coated Polystyrene/Graphite Microspheres

摘要

Polymeric ultra-low-density (ULD) proppants were successfully synthesized through the coating of 20-40 mesh polystyrene/graphite microspheres by epoxy/phenolic. The coated microspheres had very low densities of 1.038-1.080 g/cm(3) and were suspended in 5 wt% NaCI aqueous solution. Scanning electron micrographs showed that the coated microspheres had good sphericity (>= 0.9) with a smooth coating layer of 12.7 mu m. When a crosslinked epoxy/phenolic resin layer was introduced, the acid solubility, thermostability, and compression strength of the coated microspheres were dramatically improved. When the concentration of resin impregnating solution was reached 40%, the optimal performance of ULD proppants was achieved, and the following characteristics were obtained: (1) acid solubility as low as 0.06%; (2) 5% weight loss temperature as high as 378 degrees C; (3) percentage of damage as low as 1.2% at 68 MPa.