摘要
聚晶金刚石复合片(PDC)钻头在陇东致密油井作业时出现胎体裂纹和刀翼断裂的问题,严重影响了整个钻头的使用寿命和钻井时效。针对此问题,通过理化性能试验,分析PDC钻头胎体化学成分、力学性能、硬度和金相组织,采用电子显微镜扫描和能谱分析,对PDC钻头裂纹断面的物质进行定量。基于热-弹塑性理论,建立PDC钻头胎体热应力模型,探究预热温度和银钎焊温度对PDC钻头胎体的影响,提出了PDC钻头制造工艺改进措施,开展了现场试验。结果表明:热应力是引起PDC钻头开裂的根源,残余应力和组织应力共同作用是PDC钻头开裂的直接原因;PDC钻头胎体残余应力主要集中在刀翼根部和水眼部位,以1、4号刀翼和3、5号水眼最为显著;PDC钻头胎体与复合片钎焊温度过高会产生较大残余应力,钎焊温度在700℃、胎体预热温度在380℃为宜;改进预热温度和钎焊温度后的PDC钻头施工并未有断裂异常,可以安全作业。
The polycrystalline diamond composite(PDC)drill bit in Longdong tight oil well operation appears carcass cracks and cutter flank fracture,which seriously affects the service life of the whole drill bit and drilling time.In view of this problem,the chemical composition,mechanical properties,hardness and metallographic organization of the PDC drill bit carcass were analyzed through physical and chemical performance tests,and the substances in the cracked section of the PDC drill bit were quantified by electron microscope scanning and energy spectrum analysis.Based on the thermal-elastic-plastic theory,the thermal stress model of PDC drill bit carcass was established,the effects of preheating temperature and silver brazing temperature on PDC drill bit carcass were investigated,and improvement measures for the manufacturing process of PDC drill bit were put forward,and on-site tests were carried out.The results show that:thermal stress is the root cause of PDC bit cracking,and the joint action of residual stress and tissue stress is the direct cause of PDC bit cracking;the residual stress in PDC bit carcass is mainly concentrated in the root of the cutter flank and the water eye area,No.1 and No.4 cutter flanks,and the No.3 and No.5 water eyes are the most significant;high brazing temperatures of PDC bit carcass and composite piece can generate large residual stresses,the brazing temperature is at 700℃,and the preheating temperature of the carcass is at 380℃;the construction of the PDC drill bit with improved preheating and brazing temperatures has no fracture abnormality,and it can be operated safely.
作者
陈霖
贺育贤
马海云
张慧
庞合善
陈伟林
易先中
CHEN Lin;HE Yuxian;MA Haiyun;ZHANG Hui;PANG Heshan;CHEN Weilin;YI Xianzhong(School of Mechanical Engineering,Yangtze University,Jingzhou Hubei 434023,China;CCDE Changqing Drilling Engineering Company,Xi′an Shaanxi 710021,China;CNPC Changqing Oilfield Company,Qingyang Gansu 745000,China;CCDE Changqing Cementing Company,Xi′an Shaanxi 710021,China)
出处
《机床与液压》
北大核心
2024年第20期26-34,共9页
Machine Tool & Hydraulics
基金
国家自然科学基金面上项目(51974035)
湖北省重点研发计划项目(2020BAB055)。
关键词
PDC钻头胎体
热应力
断裂失效
金相组织
理化性能
PDC drill bit carcass
thermal stress
fracture failure
metallographic organization
physical and chemical performance
