钻头

It is pointed in this paper that the key of bits hydraulic design is to optimize flow field structure from the view of 3-D flow, and combining with CFD techniques to design and optimize bit hydraulics will be good to make domestic bit research progress.

本文首先提出以旋转系统内部三元流动理论去研究井下流场结构是钻头水力设计的关键，并指出借助CFD计算技术设计流场和优化钻头设计将更有利于我国钻头水力研究的发展。

According to various of the technical difficulties such as low drilling efficiency in hard rock and short service life of diamond drilling bit, analysis was made on the inherent links between blade-extruding of hot-pressing diamond and rock abrasiveness.

中文摘要：针对在坚硬致密岩石中钻进时效低和钻头使用寿命短的技术难题，分析了热压钻头的金刚石出刃与岩石研磨性等岩性之间的内在联系，认为钻头的胎体成分及其性能是关键，硬而带脆性的胎体性能有利于金刚石出刃，从而能提高钻进速度。

To the same kind of rocks, the penetration rate increases with the increases of electric bit thermal power. When electric bit thermal power keeps fixedness, the penetration rate increases in various degrees with the increases of bit load in difference rocks. Increasing the bit load is beneficial to improve the quality of glass hole wall, but the bit load should not be too big.

对于同一种岩石，钻进速度随钻头电热功率的增大而增大；当钻头电热功率不变时，根据所钻岩石岩性的不同，钻进速度随钻头轴载的增大而不同程度地增大，增加钻头轴载有利于提高玻璃状孔壁的质量，但不宜过大。

The paper includes the kinematics of PDC bit, the rock cutting mechanism of a single PDC cutter and multiple PDC cutters, the design theory and method of the spatial orientation of PDC cutter work surface, the arrangement, theory and method for placing PDC cutters onto bit body, and so forth.

研究内容包括PDC钻头运动学、PDC钻头单齿破岩规律、重迭及覆盖条件下PDC切削齿的破岩规律、PDC钻头切削齿工作面空间方向的设计理论及设计方法、PDC钻头设计时的布齿理论及布齿方法等。

The new bit ′ s cone and bearing are much larger than those of the three cone bit with the same size,therefore the new bit can bear a greater WOB,thus,the life of the bearing and cone can be prolonged and then the penetration rate can be raised and the length of bit run prolonged.

与相同钻头尺寸的三牙轮钻头相比，该新型钻头的牙轮尺寸和轴承尺寸要大得多，因此，它可以承受较大的钻压，从而可以提高轴承和牙轮的使用寿命，进而提高机械钻速和钻头的使用寿命。

Danyang Century Mingrui Tools CO., Ltd mainly specializes in the production of various tooling products, such as tct saw blade, diamond saw blade, hss twist drill bits, hole saw, wood flat drill bits, masonry drill bits, wood auger bits and hammer drill bits etc.

丹阳市世纪明瑞工具有限公司主要从事生产各种模具产品，如TCL通讯锯片，金刚石锯片，高速钢麻花钻钻头，开孔器，木材单位钻头，石工钻头，螺旋钻头和木锤钻头等

In order to solve the existing problems of drilling gravel and cobble stratum,common tungsten carbide-insert drill bits, composite diamond-tungsten carbide button bits and impregnated diamond-tungsten carbide bar bits were designed and tested successively.

针对卵砾石地层的钻进实践，先后设计与试验了三种类型的钻头；普通八角合金钻头、金刚石-硬质合金复合球齿钻头与孕镶金刚石-针状合金复合式钻头。

By means of numerical solution method, drillstring's finite element models, and based on mechanical models of bit/rock interaction, the dynamic models for lateral vibration of a cone bit are established. The contact models of bit/wellbore interaction are created on the basis of the experimental data.

为探寻在实际钻井过程中钻头的运动轨迹和与井壁碰撞时撞击力的变化规律，利用有限元方法，建立钻柱横向振动的有限元动力学模型，并在考虑钻头-岩石互作用力学模型的基础上，建立了钻头横向振动动力学仿真模型，通过实验及相关数据得到预测钻头与井壁碰撞时撞击力大小的计算公式。

Analysis is made on block effect to cutters of PDC bit with 3 factors: different top shape,cutter-distributing and wearing degree.By the interaction(radial range and altitude difference of each cutter) of three adjacent cutters,the cutter block is further analyzed with these factors,but wearing degree is simplified to be considered as the cutters vertical to the assembling plane.

中文摘要：对PDC钻头冠部形状及不同的布齿密度和切削齿在不同的磨损状态下对PDC钻头切削齿受力的影响进行了分析；用相邻的3个切削齿之间的关系（不同的切削齿与切削齿之间的径向距离和切削齿之间的高度差）来分析PDC钻头冠部形状和切削齿布齿密度对切削齿受力的影响，以及将切削齿的磨损状态简化成与切削齿在钻头上装配方向垂直的平面来分析切削齿磨损状态对切削齿受力的影响。

It is a good fundament for the computer simulation on working action of rock bit drilling.

从仿真结果可以看出，钻头在钻井过程中由于牙齿在井底的交替吃入以及井底本身的凹凸不平造成钻头在井底的纵向振动，其钻压的振幅一般为平均钻压的30%左右；同时，由于钻头在井底的刮切作用造成了钻头转速以及扭矩的变化，转速的变化相对来说较为平缓。

Methods: Five patients with parkinsonism or dystonia were assigned to general anesthesia using an modified endotracheal tube.

本实验依照人体实验之相关规定进行，五位患有帕金森氏症或肌张力异常的病人接受神经立体定位手术。

If you can benefit from this book, it is our honour.

如果您能从本书获益，这将是我们的荣幸。