Numerical Modeling and Parametric Assessment of Proppant Flow in Fractured Reservoirs

Numerical simulation of proppant flow through a single idealized rectangular fracture in a reservoir has been conducted to understand the effect of various physical and operational parameters on proppant placement within a fracture. A three-dimensional Computational Fluid Dynamics model with a Eulerian-Granular (also referred to as Eulerian-Granular or Two-Fluid) model for solid particle transport simulations has been used to study the movement of proppant particles through this idealized single fracture. In the Eulerian-Granular method, the fluid-particle mixture is represented by two-phase interpenetrating continua with the particulate matter treated as a separate continuous phase. This Eulerian-Granular method depends on constitutive relationships to model additional terms for the solid phase. Parametric assessment has been carried out to analyze the influence of proppant size on the proppant settling behavior. In addition, the effects of fracture width and the effect of fluid viscosity have been studied. The simulations resolved the complex particle-particle as well as fluid-particle interactions. Computed results indicate that the proppant settling and fracture filling patterns depend on injected proppant size, with use of larger proppants, resulting in a relatively lower filling fraction. Results also show that lowering the fracturing fluid viscosity helps to disperse proppant particles more uniformly within the fracture. Narrower fractures have more pronounced wall effects that impede proppant movement, resulting in poorly filled fracture volume.