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.

水力径向钻探是增加低产油气井产量的有效技术。为了提高该技术的运行效果，提出了一种新型的直接旋转混合射流喷嘴，并通过理论，实验和数值模拟相结合的方法研究了该喷嘴的钻孔性能。首先，建立了所提出的直接旋转混合喷射喷嘴的钻井性能的理论和数值模拟模型。实验结果表明，理论计算与仿真结果基本吻合，验证了理论和数值仿真模型的有效性。然后，在理论和数值模拟的基础上，获得了关键参数对所建议的直喷混合喷嘴的钻井性能的影响，并推导了一种综合性能更好的新型喷嘴结构参数组合。最后，通过对四种不同类型喷嘴的钻孔性能进行比较表明，所提出的直接旋转混合喷射喷嘴的破岩效果和推进性能更好。研究结果可为结构设计提供理论支持，并可显着提高水力径向钻进效率。对四种不同类型的喷嘴的钻探性能进行比较表明，所提出的直接旋转混合喷嘴的破岩效果和推进性能更好。研究结果可为结构设计提供理论支持，并可显着提高水力径向钻进效率。对四种不同类型的喷嘴的钻探性能进行比较表明，所提出的直接旋转混合喷嘴的破岩效果和推进性能更好。研究结果可为结构设计提供理论支持，并可显着提高水力径向钻进效率。