Numerical investigation of proppant transport at hydraulic-natural fracture intersection

Abstract

The transport mechanism of particles at fracture intersection is numerically studied by the coupled lattice Boltzmann-discrete element methods. First, the numerical method is validated via a benchmark test of the relative suspension viscosity. Second, a comprehensive parametric study on proppant transport through a T-junction is performed. The impacts of various parameters, including particle concentration, particle size, the Reynolds number and the fracture intersection angle are investigated. The results show that the proppant leak-off ratio decreases with particle concentration due to retardation and the Reynolds number due to inertial migration, and increases with fracture aperture. Particularly, the results also reveal a critical intersection angle of 60° at which the particle leak-off ratio reaches a maximum. Finally, an empirical expression is proposed to evaluate the particle leak-off ratio. The outcomes provide new insights into proppant transport in fracture networks and assist in an improved fracturing fluid design for naturally fractured reservoirs.