最近几年在石油钻头的改进方面有了很大进展,这些进展主要集中在密封轴承硬质合金镶齿钻头上.自从二十世纪初生产了第一批牙轮钻头以来,各制造厂曾不断地发展了一些新设计并提高了牙轮钻头的操作性能。这些制造厂曾为各种井径和地层提供了大量的钢齿钻头.这些钻头基本属于软、中硬和硬地层三种类型。在满足这三类钻头的要求时,钻头的设计必须尽量利用轴承、齿和牙轮所占有的空间,使他们的尺寸互相适应。 Much progress has been made in recent years in the improvement of oil drills, mostly in the sealed bearing carbide inserts, which have been at the forefront since the first roller cone bits were produced in the early twentieth century Some new designs have been developed and the performance of roller cone bits has been improved. These factories have provided a large number of steel bit for a variety of borehole and formation.These drill basically belongs to the soft, medium and hard formation of three types. In meeting the requirements of these three types of drill bits, the design of the drill bit must make the best use of the space occupied by the bearings, teeth and cone to adapt their dimensions.