Revealing the Effect of Bifurcated Fractures and Fluid Parameters during Multiphase Slurry Transport

Abstract

The proppant placement optimization is a critical aspect for the success of hydraulic fracture operations. However, the proppant transport in branched complex fracture networks is still elusive. We have adopted the coupled Eulerian–Lagrangian approach to quantify the proppant distributions in the main fractures, secondary fractures, and tertiary fractures in designated fracture branch units. We validated our approach against recent experimental and modeling studies where good agreements are achieved. We found that the fracture network case with secondary and tertiary fractures receive more proppant from the main fracture than the one with the secondary fractures under the same fracture volumes. Interestingly, the viscosity of the fracturing fluid enhances the transport of the proppant to the secondary fractures, while this observation becomes ambiguous when fracturing viscosity (especially low viscosity fracturing fluid) moves toward its lower end. In addition, it is observed that as the angle between the secondary fracture and the flow direction increases, less proppant is transported to the secondary fractures til an angle where the proppant is unable to be delivered to the branched fractures at 45°. This work provides enriched insights to better optimize the proppant placement in complex fracture networks.