Migration and plugging for temporary plugging balls in a multi-cluster fractured horizontal well

Ball-throwing temporary plugging technology addresses non-uniform fracture propagation in multi-cluster fracturing, though controlling ball movement for effective sealing remains challenging. This study investigates the migration of temporary plugging balls in horizontal wells using experimental and numerical simulation approaches. The two-phase flow dynamics of the fracturing fluid and the ball are simulated using a coupled computational fluid dynamics-discrete element method, and the accuracy of this method is validated through experimental testing. The results demonstrate that a reduction in the ball velocity before entering the perforation cluster, combined with an increase in the radial displacement of the ball, is conducive to achieving effective temporary sealing of the perforation. Furthermore, the influence of ball and fracturing fluid parameters on the migration is systematically examined. The results indicate that the critical value for effective perforation plugging falls within a ball-to-perforation diameter ratio range of 1.08–1.15. The injection rate of the fracturing fluid primarily affects the ball's velocity, while the fluid viscosity predominantly influences the ball's radial displacement. Optimal conditions for migrating the ball to the perforation and achieving successful sealing are observed at an injection rate of 4 m3/min and a viscosity of 18 mPa s. By analyzing the two-phase flow dynamics of the fracturing fluid and the plugging ball, this study provides optimized parameters for ball size and fracturing fluid injection, offering valuable insights for enhancing the development efficiency of unconventional oil and gas resources.