Numerical Simulation of Hydraulic Fracturing in a Discrete Element System

Hydraulically induced fracture in an assembly of cohesionless discs is numerically simulated using a discrete element model, consisting of discrete particles coupled with an interLvoid fluid flow model. Grains are represented by circular discs; to simulate flow, a geometrically coupled channel network is created by assigning nodes to pores, and flow channels to pore throats. Flow rates in channels are assumed to be proportional to the pressure gradient according to the Hagen-Poiseuille equation. The paper describes the main features of the model and explains the fracture initiation due to fluid injection and the propagation process at a grain level.