潜孔锤钻头PDC球形切削齿失效分析

Failure analysis of PDC spherical cutter for drill bit

摘要:

空气潜孔锤钻井技术作为地热资源勘探与开发的关键技术之一，其效率和效果在很大程度上取决于潜孔锤钻头的性能，尤其是PDC球形切削齿的质量和寿命。针对目前空气潜孔锤钻头钻进中切削齿出现断裂、脱落以及磨损严重导致的钻进效率低、使用寿命短等问题，本文对PDC球形切削齿进行宏观和微观分析，探究其失效原因和失效机理，并针对性地提出相应改善措施。研究结果显示：PDC球形切削齿的主要失效形式为齿的断裂、磨损及脱落。切削齿失效的主要原因是由于冲击破岩过程中切削齿同时受到切向冲击压缩和法向拉伸应力而造成损伤，同时切削齿材料本身的性能较差、金刚石层与硬质合金基体两相结合强度不高也是失效的重要原因。为了提高PDC球形切削齿的性能和使用寿命，可以通过优化钻井参数和调整外部作业条件来减轻切削齿的应力负担。此外，对PDC球形切削齿的材料配方、结构设计和制造工艺进行创新和改进，也是提升其抗冲击能力和耐磨性的有效途径。通过这些综合性能的改进措施，可以有效提升PDC球形切削齿的可靠性，进而提高潜孔钻井的作业效率和钻头的使用寿命。

Abstract:

As one of the key technologies in the exploration and development of geothermal resources, the efficiency and effect of DTH hammer drilling largely depend on the performance of the drill bit, especially the quality and life of PDC spherical cutters. In response to the current issues such as low drilling efficiency and short service life due to the breakage, detachment, and severe wear of cutter in air-assisted percussive drill bits. This paper conducts a macroscopic and microscopic analysis of the PDC spherical cutter, investigates the causes of failure and the failure mechanisms, and proposes targeted measures for improvement. The results show that the main failure modes of PDC spherical cutters are tooth fracture, wear and fall off. The main reason for the failure of the cutter is that the cutter is damaged by tangential impact compression and normal tensile stress at the same time, while the poor performance of the cutter material itself, and the combination strength of the diamond layer and the cemented carbide matrix are also important reasons for the failure. In order to improve the performance and service life of PDC spherical cutters, the stress burden of the cutters can be reduced by optimizing drilling parameters and adjusting external operating conditions. In addition, innovation and improvement of the material formulation, structural design and manufacturing process of PDC spherical cutters is also an effective way to improve its impact resistance and wear resistance. Through these comprehensive performance improvement methods, the reliability of PDC spherical cutters can be effectively improved, thus improving the operational efficiency of downhole drilling and the service life of the bit.