Proppant transport in a planar fracture: Particle image velocimetry

Particle Image Velocimetry (PIV) is a well established technique used to measure displacements in fluids. Proppant transport and placement is a crucial phase in the process of well completion to stimulate production in gas and oil reservoirs. Proppant (a granular material) is injected along fluids during hydraulic stimulation to prop fractures open after hydrocarbon production is initiated. This work presents results on the use of PIV for the study of the transport of proppant in a large laboratory scale flat vertical fracture. Velocity and vorticity profiles were analyzed for different flow rates during the transport and settlement of the proppant inside the fracture. High flow rates, compatible with field operations are achieved in this setup. The results indicate that vortexes are present in a large portion of the system and that a non-linear interplay between the settling dune and the main vortex seems to determine the time at which a fast dune growth occurs in the fracture.