Numerical investigation of fluid flow in fracture junctions with consideration to effect of fracture morphology

Abstract

Abstract Because the fracturing fluid flow at fracture junctions directly affects the proppant distribution in fracture networks, it is very important to quantitatively investigate the fluid flow in fracture junctions. In this study, the fluid flow in a laboratory‐size fracture junction was investigated, and equations for calculating the fluid split ratio were established. The correlations between the pressure loss coefficients and the width ratio, approaching angle, and fluid split ratio were obtained by simulation. Using a custom‐made Visual Basic program, the fluid split ratios in an actual‐size fracture or complex fracture networks with several secondary or tertiary fractures were calculated. The results reveal that the fluid split ratio is significantly affected by the approaching angle and width ratio in laboratory‐size fractures. In contrast, in an actual‐size fracture junction, the fluid split ratio is mainly affected by the length of the fracture channel and the width ratio. The split ratios in laboratory‐size and real‐size fracture networks with several secondary or tertiary fractures are quite different, which indicates that the split ratio should be quantitatively estimated when investigating the proppant distribution by experiment or simulation. The findings of this study can be useful in the quantitative investigation of the proppant distribution in fracture networks.

Keywords

• computational fluid dynamics
• dividing flow
• fracture networks
• pressure loss coefficient
• split ratio