Study On The New-type Multiple Drill Bit

In the engineering fields of petroleum, geology and so on, a drill bit is a major rock-breaking tool. In recent several decades, there has come out constant advancements of drill bit technology and lots of achievements. At the same time some new problems emerge in the development. Take an example, the gage protection of a bit is becoming more and more important in it's application with the development of horizontal well drilling technology and that of deep well drilling technology. However, because of the lag of material and art the gage protection has become a bottleneck problem for the bit designer to break through. In the meantime, under the guideline of "benefit first", it is desired that there is a multiple drill bit "with multifunction more than drilling" in order to shorten the journey and improve the effect and efficiency.The paper is after the full investigation of the related documents and patents at home and abroad. Some advanced technology and means are also introduced such as nanotechnology, intelligent technology, systematic research method and so on. In the mean time, it is found that the gage protection and the multifunction deserve to be studied for rock-crushing tools. The design that the active protection is taken in the paper is a breakthrough of common methods of gage protection. On the basis of the well-done roller cone bits and PDC bits, three practicable schemes are provided. As a result of selection and design, two brand-new multiple drill bits are invented, that is, protector-tri-cone MDB and protector-single-cone MDB.The knowledge and analytic methods of different disciplines are combined in the design, one example is to analyze how the self-adaptable gage protector works by analogy with the close-loop automatic control system with disturbance; another is to usehydromechanics to study the working conditions of the MDB in bottom. Meanwhile, modern methods of CAD&CAE are available in building models and FEA.