Drilling performance analysis of a new type of direct-rotating mixed-jet nozzle.

Hydraulic radial drilling is an effective technique to increase the production of low-yield oil and gas wells. To improve the operation effect of this technology, a new type of direct-rotating mixed-jet nozzle is proposed, and the drilling performance of the nozzle is studied by combining theoretical, experimental, and numerical simulations. Firstly, the theoretical and numerical simulation models for the drilling performance of the proposed direct-rotating mixed-jet nozzle are established. The experimental results show that the theoretical calculations are in near agreement with the simulations, which verifies the effectiveness of the theoretical and numerical simulation models. Then, the influence of the key parameters on the drilling performance for the proposed direct-rotating mixed-jet nozzle is obtained based on the theoretical and numerical simulation models, and a new type of nozzle structure parameter combination with a better comprehensive performance is derived. Finally, comparing the drilling performance of four different types of nozzle shows that the rock-breaking effect and propulsion performance of the proposed direct-rotating mixed-jet nozzles are better. The research results can provide theoretical support for structural designs and can significantly improve the efficiency of hydraulic radial drilling. • A new type of direct-rotating mixed-jet nozzle structure is proposed in this paper. • The work principle of the new type of direct-rotating mixed-jet nozzle is revealed. • The influence laws of key parameters on the drilling performance of the new nozzle are obtained. • It is indicated that the drilling performance of the new nozzle is better. [ABSTRACT FROM AUTHOR]