Optimization of high-frequency pulsed jet oscillation chamber structure and analysis of its pulse oscillation effects
A high-frequency self-excited pulsed jet generator was designed to address the limitations of pulsed jet applications in deep wells.A mathematical and physical model for flow field analysis was established,and the pressure fluctuation characteristics of the flow field were analyzed using the transient fluid dynamics simulation software Xflow,and the results were validated through indoor experiments.The research results indicate that the optimized jet generator chamber structure has a chamber width of 61 mm,an inlet width of 20 mm,and a model thickness of 40 mm.The outlet pressure fluctuation frequency is 296 Hz,which meets the design requirements of around 300 Hz;By combining the optimized structure with the actual drill bit flow channel,it was found that the tool can generate high-frequency stable fluctuating pulse jets.The oscillation frequency of the axial force in the oscillation chamber is 276 Hz,and the tool pressure drop is around 5 MPa.By optimizing the structure of the pulsed jet generator,stable high-frequency flow field pressure fluctuations were obtained,which can further improve the bottom-hole cuttings cleaning and auxiliary rock breaking effectiveness of pulsed jet,and promote the development of pulsed jet deep well ROP increasing technology.