  This paper investigates proppant flow and transport in intersected fractures
at angles typical for intersections of pre-existing and new hydraulic
fractures. Proppant is small granular material, which is placed into hydraulic
fractures during geothermal and hydrocarbon reservoir stimulation and props the
fluid paths open during reservoir exploitation. This study uses plexiglas
laboratory slot experiments enhanced with an advanced image analysis for
identifying particle trajectories and quantifying slurry velocities. Although
proppant flow and transport has been broadly studied, the effects of
intersecting fracture angles have not, especially coupled with fluid
viscosities, flow rates, and proppant volumetric concentration effects. This
paper specifically investigates the role of intermediate fracture angles, which
have been identified to occur most frequently when the new hydraulic fractures
intercept the existing ones. Results show that proppant flow and transport
behavior after the intersection is very sensitive to carrying fluid viscosity
and flow rates alteration, while differentiating proppant volumetric
concentrations have a limited effect. Fracture intersection angle itself has a
clear effect on proppant flow velocities and proppant settlement; furthermore,
it enhances the effects from fluid viscosity, fluid flow rates, and proppant
volumetric concentrations.
