直旋混合射流钻头流场及关键参数研究

Study on Flow Field and Key Parameters of Straight-swirling Mixing Jet Bit

水力喷射径向钻井技术中核心部件为水射流钻头,对钻进效率和开采效果有着决定性影响,而直旋混合射流钻头兼具扩散角度大、轴线速度高的优势,满足水力喷射径向钻井的技术要求。为了得到直旋混合射流钻头最优结构参数,利用数值模拟方法,分析不同参数的钻头流场三维速度沿径向、轴向的分布规律,对比得到叶轮的最优参数:叶轮长度5 mm、叶轮槽个数6个、腔收缩角60°。最后通过钻头钻孔试验对不同叶轮槽数量的钻头钻孔性能进行分析,验证了仿真结果的正确性。

The core component of the hydraulic jet radial drilling technology is the water jet bit, which has a decisive influence on the drilling efficiency and mining effect. The straight-swirling mixing jet bit has the advantages of large diffusion angle and high axial velocity. It is suitable for the technical requirements of hydraulic jet radial drilling. In order to obtain the optimal structural parameters of the straight-swirling mixed jet bit, used numerical simulation methods to analyze the radial and axial distribution law of the three-dimensional velocity of the bit flow field with different parameters, and obtained the optimal parameters of the impeller by comparsion: the impeller length is 5 mm, the number of impeller grooves is 6, and the cavity shrinkage angle is 60°. Finally, the drilling performance of the bit with different numbers of impeller grooves was analyzed through the bit drilling experiment,which verifies the correctness of the simulation results.