Energy Concentrated and Self-Resonating Mini-Extended Jet Nozzle Used for Jet Drilling

Abstract

Theoretical, experimental, and field test studies of the self-resonating pulsating jet have been carried out. The interaction mechanism of vortices and outlet wall is described. On the basis of theoretical calculations and experimental data, a new mini-extended and energy concentrated self-resonating pulsating jet nozzle can be recommended. Hydrodynamic experiments, rock erosion tests, and field tests in a drilling engineering environment were carried out using the new nozzle. The results show that the new nozzle has stronger erosion capability than the cone-type or conventional organ-pipe self-resonating nozzle jet. The field test results in drilling engineering show that the outlets of the newly designed nozzles have strong anti-scouring ability. The new exit design of the nozzle can increase its life span.