仿生PDC切削齿结构设计与破岩机理研究

发布时间：2018-04-02 18:47

本文选题：PDC钻头　切入点：切削齿　出处：《西南石油大学》2015年硕士论文

【摘要】：随着我国油气钻探向着深井和复杂地层油气藏的进发,日趋复杂的井下工况和地层难钻性等都为钻井工具带来了极大困难和考验。目前PDC钻头在实际钻井作业中存在崩齿、断齿等现象,从而导致钻头失效的问题。切削齿是PDC钻头的基本切削单元,其结构性能直接影响钻井效率和PDC钻头的使用寿命。本文运用仿生学原理开展新型仿生PDC切削齿的结构设计,通过系统、细致的对土壤动物蝼蛄的爪趾、穿山甲的鳞片结构进行分析研究,将其中蕴含的生物学原理运用到新型仿生PDC切削齿结构的设计中,设计出了一种具有分层破岩,减振防损的齿形。新型仿生PDC切削齿异于传统切削齿的破岩机理,改变了破岩方式,使得新型仿生PDC切削齿易于吃入地层,齿的阶梯结构更有利于岩石的剥离。再者,借助有限元分析手段,对新型仿生PDC切削齿与常规切削齿进行单齿和全钻头的仿真模拟对比分析,结果表明,新型仿生PDC切削齿的性能明显优于常规切削齿。同时开展了相关的单齿破岩试验研究。论文主要取得的成果： (1)基于蝼蛄爪趾形态仿生和穿山甲鳞片结构仿生,设计了一种新型仿生PDC切削齿。相对于传统的切削齿,仿生PDC切削齿改进了破岩方式和改善了受力状态。 (2)借助经典弹性力学和Hertz接触理论对常规圆柱齿与岩石的接触力学行为进行简单的描述,推导了它们的接触压力分布及接触参数计算式,并推广至仿生齿的接触计算中。 (3)不同切削齿破岩的仿真模拟对比研究表明,仿生齿的诸多关键性指标都优于常规圆柱切削齿。在相同钻井参数和工况下,仿生PDC钻头最大破岩扭矩约降低了33.3%,岩石能量侵入率提高62.5%,充分说明了仿生齿结构设计的正确性,同时佐证了运用仿生学原理进行切削齿仿生设计的可行性。 (4)开展了不同切削齿的单齿破岩实验研究,实验结果表明：在相同吃深、切削速度及外部条件下,仿生齿的切削力为常规圆柱齿的50.94%。
[Abstract]:With the development of oil and gas drilling towards deep wells and complex reservoirs in China, the increasingly complex downhole conditions and formation difficult to drill have brought great difficulties and tests for drilling tools.At present, PDC bit in the actual drilling operation, such as tooth collapse, broken teeth, resulting in the failure of the bit.Cutting tooth is the basic cutting unit of PDC bit. Its structure and performance directly affect drilling efficiency and service life of PDC bit.In this paper, the structure design of the new bionic PDC cutting teeth is carried out by using the bionic principle. The structure of the claw toe and pangolin scale of the soil animal mole cricket mole cricket is analyzed and studied through the system.Applying the biological principle to the design of a new bionic PDC cutting tooth structure, a tooth profile with layered rock breaking and vibration reduction and loss prevention is designed.The new bionic PDC cutting teeth are different from the traditional cutting teeth in rock breaking mechanism, which changes the rock breaking mode, makes the new bionic PDC cutting teeth easy to eat into the strata, and the ladder structure of the teeth is more favorable for the peeling of rocks.Furthermore, by means of finite element analysis, the performance of the new bionic PDC cutting tooth is obviously superior to that of the conventional cutting tooth, which is compared with that of the single tooth and the full bit. The results show that the performance of the new bionic PDC cutting tooth is obviously superior to that of the conventional cutting tooth.At the same time, the related experimental study of single tooth rock breaking is carried out.The main achievements of the thesis are as follows:A new bionic PDC cutting tooth was designed based on the bionic morphology of talon toe and the scale structure of pangolin.Compared with the traditional cutting teeth, the bionic PDC cutting teeth improve the rock breaking mode and the stress state.(2) the contact mechanics behavior between conventional cylindrical teeth and rock is simply described by means of classical elastic mechanics and Hertz contact theory, and their contact pressure distribution and contact parameters are derived, which is extended to the contact calculation of bionic teeth.3) the simulation and comparison of different cutting teeth show that many key indexes of bionic teeth are better than those of conventional cylindrical cutting teeth.Under the same drilling parameters and working conditions, the maximum rock breaking torque of bionic PDC bit is reduced about 33.3and the rock energy invasion rate is increased by 62.5, which fully shows the correctness of the bionic tooth structure design.At the same time, the feasibility of bionic design of cutting teeth is proved.The experimental results show that the cutting force of the bionic teeth is 50.94 of the conventional cylindrical teeth under the same cutting depth, cutting speed and external conditions.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE921.1

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