Experimental investigation of particle transport behaviors and distribution characteristics in a dual-branch fracture with rough surfaces

Particle transport in dual-branch fractures is a common but poorly understood element of hydraulic fracturing . The model with two-sided rough surfaces is first developed. The particle image velocimetry method analyses the slurry flow. The results reveal that the model can hinder particle transport. T-junctions and rough surfaces cause particle-wall collisions, leading to particle settling. Flow diversion into the dual branches reduces fluid velocity, forming a high sand bed. The bed in the primary fracture can block the injection hole at low rates. The structural and dimensional differences between the two branches induce non-uniform flow resistance. The lower the flow resistance, the smaller the particle bed in the branch. Progressive advancement and horizontally layered stacking are two accumulation patterns. Small particles easily flow deeper into the fracture through the natural fracture , especially in high-viscosity and high-speed slickwater. A correlation model is proposed for quantitatively predicting bed coverage in a dual-branch fracture. • The slurry flow in a dual-branch fracture with rough surfaces is investigated by the experiment. • The particle image velocimetry method can describe the complex flow in the rough pathway. • The effects of key factors on the slurry flow are investigated. • A dimensionless model is proposed to to predict the particle coverage area.