Effects of proppant distribution in fracture networks on horizontal well performance

In this paper, we presented a coupled 3D finite element method model for the simulation of proppant transport in fracture networks and its effects on horizontal well performance. We used a mixture model, which have advantages to deal with two-phase flow containing a dispersed phase like solid particles, to simulate the proppant transport process in fracture networks. Then a tight oil reservoir model was established to evaluate the effect of the proppant distribution on the horizontal well performance. The effects of several factors, such as the proppant physical properties and injection parameters, were analyzed. The calculated results show that, in the fracture network, proppant accumulates at the intersections of cracks. Height of the proppant packed bed in natural fracture was about 30% smaller than that in the main hydraulic fracture, and the communication between hydraulic fractures leads to a larger proppant dune and higher conductivity. Besides, in a tight oil reservoir, the proppant distribution has a significant influence on the well performance. When the reservoir permeability is reduced to 0.05 mD, the productivity index fold of increase calculated including the proppant uneven distribution can be 47.7% larger than that calculated with idealized proppant distribution. Furthermore, the proppant physical properties and injection parameters are found to be correlated with the fracture network conductivity. Based on this analysis, optimum proppant injection conditions can be identified. © 2019 Elsevier B.V.