Modeling of dynamic bridging of solid particles in multiple propagating fractures

Abstract

During multi-cluster fracturing, solid particles are widely used to alleviate the non-uniform fluid distribution and fracture growth. Even though diversion technology has been applied and proved effective in numerous field applications, many involved physical mechanisms, such as solid diverters transport, settling, bridging, and packing in multiple propagating fractures, remain unclear. In this work, a computational mechanics system is developed to interpret the coupling process of fluid flow, fracture propagation, and particle transport. The moving fracture front is located using the implicit level set algorithm (ILSA) and tip asymptotic solution. The diverter particle transport model can capture the settling, bridging, and packing of particles; thus the slurry flow in the fracture can transit from Poiseuille flow to Darcy flow naturally. Application of the developed system to simulate a single stage of three equally spaced clusters indicates that it is possible to create multiple fractures with uniform length using diversion technology, but their widths are non-uniform. Instead, they demonstrate pinched or ballooned shapes, because of the stress interference. An extensive parametric study is also performed to investigate how various parameters affect diversion efficiency.