This invention belongs to the field of oil and gas
field development technology and discloses a temperature-pH dual-responsive smart fracturing proppant and its preparation method. The proppant adopts a three-layer core-shell structure, including a high-strength
ceramic or
quartz sand core, a
polyvinyl alcohol crosslinking
transition layer reinforced with nano-silica, and a poly(N-isopropylacrylamide-co-
acrylic acid)
copolymer smart response layer. In the low-temperature proppant carrying stage, the smart response layer hydrates and swells to form a gel layer, giving the proppant excellent suspension performance and
friction reduction ability, realizing water fracturing. In the high-temperature reservoir environment, the phase transformation of the temperature-sensitive segment and the
protonation of the pH-sensitive segment cause the smart response layer to shrink and detach rapidly, realizing autonomous gel breaking and aiding in fracturing. The nano-reinforced
transition layer significantly improves the anti-fracture performance, reducing the fracture rate to 6% to 11% and increasing the long-term
conductivity by 35% to 58%.