针对自掩埋钻井新方法需要内排屑的问题，采用螺旋刀翼、内锥面、中心腔体等结构设计内螺旋刀翼PDC钻头，研究刀翼螺旋升角的变化规律，分析岩屑在刀翼刃部和刀翼面上的受力，建立岩屑推动力与刀翼螺旋升角的关系，优化刀翼螺旋升角，并进行台架实验。结果表明：内螺旋刀翼PDC钻头刀翼螺旋升角的理想设计范围为9°~52°，考虑加工和排屑通道大小等影响因素，其合理的设计范围为26°~52°，研制的钻头能迫使岩屑向其中心运移，并实现岩屑的良好流动，满足内排屑要求。%New method for the self buried drilling requires moving the cuttings from the bottom hole to the inside of the drill bit, and therefore the structures of spiral blade, inner cone, center cavity and so on are used in the design of the spiral blade PDC bit. In this paper, the changing rule of blade helix angle was studied, the forces on the cuttings at the blade edge and blade face were analyzed, the relationship between the driving force on the cuttings and the blade helix angle was established, the blade helix angle was optimized, and bench experiment was carried out. The results show that the ideal design range of the blade helix angle is 9°-52°, considering the influence factors such as the process and the size of cut-tings removal channels, etc. , the reasonable design range of the blade helix angle is 26°-52°. The developed bit can force the cuttings moving into its center, and make the cuttings flowing well, and satisfy the requirements of the inner cut-tings removal.
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