Experiment on proppant transport in near-well area of hydraulic fractures based on PIV/PTV

Particle image velocimetry and laser testing technology are used to test the flow field near the well and the migration mechanism of proppant, and PIV / PTV algorithm is used to calculate the two-phase velocity distribution respectively. The results indicated that the jet from the perforation into the fracture produced a strong swirl, and the large-scale vortex structure dominated the two-phase flow. At a high injection rate, the proppant had a good follow-up to the fluid, whereas it settled and accumulated in the jet area at a low injection rate. As the flow rate, fracture width, and viscosity increased, the area affected by the vortex increased and the proppant was removed. As the pumping time increased, the moving directions of the proppant were concentrated in 0° to 45° and 315° to 360°, and the vorticity in the near-well area was enhanced. • Established a PIV/PTV experiment device to test the proppant and fracturing fluid velocity field. • Characterized by streamline and vorticity, the flow law of fracturing fluid near the wellbore is analyzed. • Revealed the mechanism of proppant migration near the wellbore via the combination of macro and micro.