空气冲旋钻头牙齿研究

【作者】 李伟；

【导师】 黄志强；

【作者基本信息】 西南石油大学 ， 化工过程机械， 2011， 硕士

【摘要】 本文针对空气冲旋钻头现场使用存在的两个问题：齿的磨损和断裂,一方面从硬质合金材料角度出发,研究不同WC晶粒度对齿的耐磨性和抗冲击性的影响,找到了能更好地满足空气冲旋钻头牙齿要求的硬质合金材料。另一方面对边齿做了力学分析,研究了边齿倾角、露齿高度以及齿形对边齿各危险点应力的影响,找到了合理的边齿参数,降低了边齿的断裂几率。同时,应用ANSYS有限元分析软件对理论计算进行验证。通过硬质合金材料的研究以及边齿的力学分析,达到提高牙齿耐磨性和抗冲击韧性,减小边齿内部应力。从达到提高牙齿使用寿命的目的,本文主要从以下几方面开展工作：(1)空气冲旋钻头的现场调研。通过对国内外钻头牙齿材料(硬质合金材料)的文献调研,了解硬质合金的特点、发展状况及研究水平,在前人研究基础上找到能适应空气冲旋钻头要求的硬质合金牙齿材料；同时,对国内外钻头牙齿力学分析做了调研分析,为本论文牙齿力学分析提供借鉴。(2)空气冲旋钻头牙齿失效分析。包括牙齿失效形式、失效机理及失效原因分析。通过对空气冲旋钻头牙齿失效分析研究,弄清钻头的失效原因,失效机理,为后续研究提供依据。(3)空气冲旋钻头牙齿材料研究。主要以试验手段研究WC的晶粒度对硬质合金材料耐磨性能和抗冲击韧性的影响关系。确定合理的WC晶粒度后,采用WC粉末制备技术、压坯成型烧结技术和抑制WC晶粒的长大技术等制备工艺制备成品牙齿,通过牙齿的性能测试、微观结构分析、耐磨性、抗冲击性能试验,以期研制出能很好满足空气冲旋钻头头要求的硬质合金牙齿材料。(4)空气冲旋钻头牙齿力学分析。通过对钻头牙齿井底受力分析,建立力学模型进行理论计算,找出牙齿内可疑危险点,分析各可疑危险点的应力与钻头边齿的露齿高度、倾角、半径以及齿形的关系,确定合理的边齿露齿高度、倾角、半径以及齿形。通过ANSYS有限元分析软件,对不同倾角和露齿高度的边齿进行仿真分析,其仿真结果和理论计算结果是比较吻合的。更多还原

【Abstract】 In this paper, we analyzed two question that are wearing and fracture of air impulse rotary drill bit teeth in field use. On the one hand from cemented carbide material standpoint, study the effects of teeth wear resistance and impact resistance with different WC grain sizes,and find the better cemented carbide materials which can meet the requirements of the teeth of air percussion-rotary bit. On the other hand make a mechanical analysis on side teeth,research the inclination of side teeth, teeth height as well as the teeth shape’s effects on side teeth’s peril points stress. Then find reasonable parameters of the side teeth and reduce the chance of side teeth fragmentation. Achieve improving wear resistance and impact resistance and reduce the stress side of teeth through researching cemented carbide materials and analysising mechanical of side teeth. So as to achieve the purpose of improving the service life. The thesis’s primary research work is as follows:(1) The scene investigates and studies on air percussion-rotary bit. Through researching literature on the overseas and domestic present status of drill teeth materials(cemented carbide materials), comprehend the cemented carbide characteristics, the development state and the reseach level. On the basis of previous research find cemented carbide teeth materials which can adapt to the requirements of air percussion-rotary bit. Meanwhile make an investigation and analysis on the mechanical of home and abroad bit teeth and provide experience in mechanical analysis of the teeth of this thesis.(2) Failure analysis of air percussion-rotary bit teeth. Include tooth failure modes, failure mechanisms and failure reason analysis. Through the failure analysis of air percussion-rotary bit teeth,understand the failure reasons of drill, failure mechanism and provide a basis for further study.(3) Researching on air percussion-rotary bit tooth materials. Mostly use experimental study means to research the affect of WC’s grain size on wear resistance and impact resistance of cemented carbide materials. Use WC powder preparation technique, forming compact sintering technology and subduing growth of WC grain size technology as well as preparatian procedure to product finished teeth after confirming the reasonable WC grain size. Through tooth performance test, microstructure analysis, wear resistance and impact resistance experiments, well develop cemented carbide tooth materials which can meet the requirements of the air percussion-rotary bit.(4) Mechanical analysis of air percussion-rotary bit. Through mechanical analysis of drill tooth in downhole, establish the mechanical model for calculation, identify the suspicious dangerous point within teeth, analyse the relationship between every stress of suspected dangerous points and the tooth height, inclination, radius and tooth form of drill side teeth. Then comfirm more rensonable ones.更多还原