Development of self-generated proppants with accelerated growth speed based on the investigation of the nano-fillers

The growth rate of self-generated proppants in fractures determines their timely compressive strength development for fracture propping. Considering the influence of filler physicochemical properties (size, density, specific surface area (SSA), thermal conductivity (TC), compatibility, etc.) on polymer microsphere strength growth, modified graphite (MG) nano-powder was designed and rapid-growth self-generated proppants were constructed. Using SPSS (ver. 22), eight inorganic fillers were analyzed. Results showed specific surface area had the greatest impact on strength growth, with influence coefficients of 0.69 for SSA, −0.54 for size, −0.39 for TC, 0.39 for compatibility, and 0.044 for density. Incorporating MG as the desired filler increased the strength growth rate of self-generated proppant microspheres by 70 % compared to pure microspheres. Consequently, using peak pressure as an indicator, the maximum peak pressure reached 52.4 N within 24 minutes at 80 °C.