PDC石油钻头钎缝强度的研究

Study on the brazing strength of PDC petroleum drill bit

简述了深井钻探PDC钻头的复杂受力状态,根据钻头损坏形式解析了PDC失效原因,分析了影响PDC钎缝的耦合性因素,针对苛刻的工况条件开展了提高PDC钎缝强度和延长钻头寿命的研究。采用扩大固溶体区域、弥散强化等钎焊材料性能优化技术提高了钎缝的强度和耐磨性;通过前置处理、温度场平衡和后续处理技术,调控钎焊工艺获得了原位生成强化的钎缝。比较了几种钎焊材料和钎焊工艺制造的深井PDC石油钻头的失效特点,工程应用效果证明:强化型钎料可以满足复杂工况下PDC的苛刻要求,钎焊材料和配套的钎焊工艺延缓了PDC的损坏,强化的钎缝在PDC正常磨损报废后仍然完整有效。

The complex stress state of polycrystalline diamond compact（PDC） drill bit working in deep well is introduced,the PDC failure reasons are analyzed according to their damaged presence,and the coupling factors affecting on the PDC brazing strength are outlined.The research on how to improve PDC brazing strength under harsh mining conditions and to extend the drilling lifetime is carried out.The technologies on optimizing brazing filler metals performance,such as expanding solid solution region,as well as dispersion-strengthening,are applied to improve the brazing strength and wear resistance.Through the pre-processing,temperature balance and follow-up processing technology,the in-situ reinforced brazing strength can be obtained by adjusting braze process.failure characteristics of oil drills manufactured with different brazing filler materials and techniques are compared and analyzed.Through application experiment,the results prove that： enhanced filler metals could satisfy the demand of PDC drill which works in various complex operating conditions;the brazing filler materials with matching process could delay PDC damage;the enhanced brazing joint is still complete and competent after PDC is discarded.