The performance of jet pumps depends significantly on their structural and operational parameters. Current research primarily concentrates on theoretical models and laboratory tests, with limited experimental investigations and comprehensive reports concerning jet pump performance under various parameter combinations. In this study, we take a comprehensive approach, integrating both experimental and theoretical methods to assess jet pump performance under optimized process parameters and sand-flushing capabilities. The key findings of this study are as follows: While the characteristic and efficiency equations of jet pumps effectively describe the interaction of critical factors, including the area ratio, pressure ratio, flow rate ratio, and density, they unfortunately do not account for the influence of crucial structural factors, such as the nozzle throat distance, throat length, and diffuser length, on overall performance. Moreover, the parameter optimization technique based on the P-M curve has limitations and requires a tailored design and evaluation to consider the maximum suction capacity in practical engineering contexts. Notably, the nozzle throat distance significantly affects the jet pump suction capacity. Increasing the nozzle throat distance from 6 mm to 12 mm substantially enhances the suction capacity, albeit with a minor reduction in the lifting capacity. Extending the distance from 12 mm to 18 mm initially boosts the suction capacity, followed by a subsequent decline, along with a decrease in the lifting capacity. Interestingly, jet pumps effectively handle sand suction at relatively low pump pressures, creating negative-pressure conditions. As the pump pressure increases, the suction capacity remains relatively stable. However, the lifting capacity increases proportionally with the pump pressure, providing valuable theoretical and technical insights for practical jet pump applications. In summary, our study introduces a comprehensive approach to evaluate jet pumps by integrating experimental and theoretical methods. These insights highlight the intricate relationship between jet pump characteristics and operational parameters, offering essential knowledge for the efficient utilization of jet pumps in various applications.

This paper addresses the critical challenge of insufficient solid-phase suction capacity in jet pumps during vacuum sand cleanout operations for low-pressure oil and gas wells. Through integrated numerical simulations validated by experimental measurements with under 15% error, a kind of nonlinear interaction mechanism among key operational and solid-phase parameters is revealed in this paper. The results demonstrate that due to intensified turbulent dissipation, particle diameters exceeding 0.5 mm will lead to a significant decrease in pump efficiency, while an increase in solid volume fraction can improve the solid transport rate but will reduce the energy conversion efficiency. Working pressure optimization shows that the pump efficiency will reach its maximum when the work pressure is 5 MPa, while if it is 8 MPa, the solid transport capacity will be increased by 116%. A discharge pressure exceeding 2.5 MPa will reduce the suction pressure difference and disrupt solid phase transport. A novel dual-metric framework considering the solid transport rate and pump efficiency is put forward in this paper, which includes limiting the particle diameter to 0.5 mm or less, maintaining a solid volume fraction below 30%, and keeping the working pressure between 5 and 8 MPa and the discharge pressure at 2.5 MPa or lower. This method can increase the sand removal efficiency to over 30% while minimizing energy loss, providing a validated theoretical basis for sustainable wellbore repair in depleted oil reservoirs.