中文摘要：

水平井钻进过程中往往因携岩不利、清岩不及时,低边堆积的岩屑床会导致托压、底部钻具组合黏托甚至卡钻等问题。为此,在分析岩屑床形成原因的基础上,基于赫姆霍兹振荡腔脉冲生成、射流泵和高压射流等理论,设计了一种新型水平井赫姆霍兹式脉冲内磨钻头——该钻头依靠高速脉冲射流辅助破岩、反向射流负压抽汲钻头底部钻屑以及内磨削结构减小钻屑粒径,实现了高效清岩破岩,减小压持效应,清除水平井岩屑床。进而分别建立了脉冲生成装置、高效破岩装置、反向抽汲装置的水力模型。模拟计算结果表明：（1）谐振最优流量随进给腔直径、反馈腔直径的增大而增大,随谐振腔直径的增大而减小,谐振最优流量与各因素近似呈线性关系;（2）反向抽汲装置的最优流量比随无量纲流量比先增大后减小,随无量纲面积比的增大而减小;（3）通过算例分析得到赫姆霍兹振荡腔固有频率为24.00 Hz,谐振最优流量为23.92 L/s,最优流量比为0.59,并经实例分析验证了水力模型的准确性。结论认为,该新型钻头为解决岩屑床的堆积问题提供了一种新的方案。

英文摘要：

If cuttings carrying performance is poor and cuttings removal is not in time during the drilling of horizontal wells, drilling cuttings will accumulate in the lower sections, leading to backing pressure, BHA binding and even drill pipe sticking. In this paper, a new type of Helmholtz pulse grinding bits suitable for horizontal wells was designed based on the theory of Helmholtz oscillation cham- ber to generate pulse, jet pump and high pressure jet after the formation of cuttings beds was analyzed. In this type of bit, a high-speed pulse jet is used to assist rock breaking, a reverse jet is used to remove the cuttings at the bottom of the bit under negative pressure, and its inner grinding structure is used to reduce the particle size of cuttings. By using this bit, efficient cuttings removal and rock breaking will be both realized, the chip hold-down effect will be reduced and the cuttings beds in a horizontal well will be also removed. Then, the hydraulic models were established for a pulse generation device, an efficient rock breaking device and a reverse swabbing device, respec- tively. It is shown from the simulation results that the optimal resonance flow rates increases with the increase of the diameters of an inlet chamber and a feedback chamber and with the decrease of the diameter of a resonance chamber, and it is approximately in linear relation- ship with each factor. The optimal flow-rate ratio of the reverse swabbing device increases first and then decreases with the increase of dimensionless flow-rate ratio, and decreases with the increase of dimensionless area ratio. It is indicated from example analysis that the inherent frequency of Helmholtz oscillation chamber is 24.00 Hz, the optimal oscillation flow rate is 23.92 L/s and the optimal flow-rate ratio is 0.59. Based on case studies, the accuracy of hydraulic models is verified. It is concluded that this new type of bits provides a new solution to the accumulation of cuttings beds.