异形单牙轮钻头牙齿载荷数值模拟与实验验证

发布时间：2018-06-22 21:10

本文选题：异形单牙轮钻头 + 牙齿载荷　；参考：《西南石油大学》2015年硕士论文

【摘要】：异形单牙轮钻头是一种新形单牙轮钻头,其设计目的是为了克服球形单牙轮钻头在硬地层和高研磨性地层中牙齿先期磨损严重的缺陷。目前该类钻头仍处于研发中,还存在很多研究空白,其中牙齿载荷是钻头设计者和使用者最关心的问题之一。依托国家科技重大专项“低渗气藏复杂地层高效钻井关键技术”下的联合研究任务“深部难钻地层高效破岩新技术研究”,本文采用有限元数值模拟与台架测试,并结合现场试验对该形单牙轮钻头展开破岩基础理论研究,包括井底模式、破岩机理、各齿圈牙齿载荷大小和分布规律,以及钻头牙齿失效机理等。具体工作内容及主要结论如下： (1)以西南石油大学申请的发明专利“一种锥形单牙轮钻头”为原型,采用三维建模软件Pro/E设计了两只不同牙轮形状的异形单牙轮钻头； (2)在实验台架上对两只钻头在不同钻压、不同岩石条件下钻进时的牙齿载荷进行了物理测试； (3)采用显式动力学有限元软件LS-DYNA建立了两只钻头与岩石的互作用有限元模型,对不同实验工况下的钻头钻进过程进行了数值模拟； (4)在完成相关数据处理的基础上,对比分析了数值模拟与台架测试得到的井底模式、钻压与钻头轴向力、牙齿载荷曲线形态以及载荷分布规律,验证了有限元法在钻头钻进过程模拟中的可靠性。分析结果表明：1)与球形单牙轮钻头主要以长距离刮削方式破岩不同的是,异形单牙轮钻头是依靠牙齿的冲击压入与剪切刮削两种方式联合作用破碎岩石,说明牙轮形状会直接影响钻头的破岩方式；2)牙齿载荷的分布规律主要与钻头结构相关,而与岩石性质无关；3)牙齿载荷分布不均匀。牙轮大端牙齿比小端牙齿的载荷大,同时锥面过渡处附近牙齿的载荷也较大,需要对牙轮形状和布齿方式进行适当优化。 (5)完成了其中一只钻头的现场试验,并对其进行了磨损失效分析。同时,以现场试验为背景,对该钻头进行有限元数值模拟,结果表明有限元分析结论与现场钻头的磨损分布规律一致,再次验证了有限元数值模拟的可靠性。本文的研究成果有助于逐步完善异形单牙轮钻头破岩基础理论,对钻头结构和布齿设计具有一定的指导意义；同时,文中采用的数值模拟方法同样适用于三牙轮钻头、PDC钻头、复合钻头等所有类型的钻头,将该方法推广到钻头产品的设计中可以有效缩短研发周期、降低成本。
[Abstract]:The special-shaped single cone bit is a new type of single cone bit, which is designed to overcome the serious defects of the spherical single cone bit in the early wear of the teeth in hard and high abrasive formations. At present, this kind of bit is still in the research and development, and there are still many research gaps, among which tooth load is one of the most concerned problems of bit designer and user. Relying on the joint research mission "New High efficiency Rock Breaking Technology in Deep hard drilling Stratum", which is the key technology of high efficiency drilling in complex formation of low permeability gas reservoir, the finite element numerical simulation and bench test are adopted in this paper. Combined with the field test, the basic theory of rock breaking of the single cone bit is studied, including the bottom hole model, rock breaking mechanism, tooth load size and distribution law of each gear ring, and the failure mechanism of the bit tooth, etc. The main work contents and main conclusions are as follows: (1) based on the invention patent "a kind of conical single cone bit" applied for by Southwest Petroleum University, Two special-shaped single cone bits with different cone shapes were designed by using the 3D modeling software Pro-E. (2) the tooth loads of two bits under different drilling pressures and different rock conditions were tested on the experimental bench. (3) using explicit dynamic finite element software LS-DYNA, the interaction finite element model between two bits and rock is established, and the drilling process of drill bit under different experimental conditions is simulated numerically. (4) on the basis of relevant data processing, the bottom hole model, drilling pressure and bit axial force, tooth load curve shape and load distribution law obtained by numerical simulation and bench test are compared and analyzed. The reliability of finite element method in bit drilling process simulation is verified. The analysis results show that the special shape single cone bit is different from spherical single cone bit in breaking rock by long distance scraping. The special shape single cone bit is broken rock by the combined action of tooth impact pressing and shearing scraping. It is shown that the shape of the cone will directly affect the rock breaking mode of the bit. 2) the distribution of the tooth load is mainly related to the structure of the bit, but not to the rock properties. 3) the distribution of the tooth load is not uniform. The load of teeth at the big end of the tooth is larger than that of the tooth at the small end, and the load on the tooth near the transition of the cone is also larger. It is necessary to optimize the shape of the tooth wheel and the method of tooth distribution. (5) the field test of one of the bits has been completed. Wear failure analysis was carried out. At the same time, based on the field test, the finite element numerical simulation of the bit is carried out. The results show that the conclusion of the finite element analysis is consistent with the field bit wear distribution, and the reliability of the finite element numerical simulation is verified again. The research results in this paper are helpful to perfect the basic theory of rock breaking of special-shaped single cone bit, and have certain guiding significance for bit structure and tooth arrangement design, meanwhile, the numerical simulation method used in this paper is also applicable to the PDC bit of three-cone bit. The application of this method to the design of drill products can effectively shorten the research and development cycle and reduce the cost.
【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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