Viscoplastic flow in intersecting fractures

Understanding viscoplastic fluid flow in discrete fracture networks is essential for natural and industrial processes, yet the hydraulic resistance at fracture intersections remains poorly characterized. This study investigates Herschel–Bulkley fluid flow through two intersecting fractures using two approaches: a full Navier–Stokes model and a reduced Hele–Shaw approximation. The Hele–Shaw model accurately predicts hydraulic resistance for Reynolds numbers up to O(10) and Bingham numbers spanning 10−2 to 1. Resistance is largely insensitive to Bingham number for Bn≲0.1, and pressure distributions are well captured by the approximation. The power-law index significantly influences resistance and pressure, with strong shear-thinning behavior increasing resistance variability by an order of magnitude and inducing channelization in the downstream fracture.