Simulations of proppant transport in propagating multiple hydraulic fractures using the multi-phase particle-in-cell method

Multi-stage hydraulic fracturing has been widely used in unconventional reservoirs. Due to the stress interference and unbalance fluid division among fractures, the propagation of fractures, as well as the proppant transport, within one stage becomes different. Few studies have simulated the transport of proppant in simultaneously propagated 3D multiple fractures, especially with Lagrangian method. To better capture the proppant behaviors in multiple fractures, a three-dimensional model, which integrates the multiple fracture propagation (displacement discontinuity method (DDM)), slurry flow in wellbore (semi-analytical method) and proppant transport (multiphase particle-in-cell (MP-PIC) method) is proposed. The role of fracturing fluid viscosity, perforation number, and proppant properties on both fracture propagation and proppant transport is investigated. The results indicate that increasing fracturing fluid viscosity enhances the uniformity of multiple hydraulic fractures and improves proppant suspension. In addition, the unbalance of fracture length is greater than proppant transport distance. Decreasing the number of perforations improves fluid distribution uniformity among different perforation clusters and results in a more uniform fracture length and proppant distribution. Reducing proppant size and density can help increase both the propped fracture length and the proppant coverage of the fracture area.