Mechanical Model And Optimizing Design Of Oriented PDC Bit

With the development of the petroleum industry, the application of directed drilling technique in the petroleum drilling engineering increases quickly and the quantity of direction well increase quickly too. During the drilling of directional well, the well track is obtained by rotary drilling and slide drilling alternately going.More and more PDC bits are used in the petroleum drilling project for the PDC bit have more long working life and faster bit penetration than the roller bit. But when the PDC bit is used drilling in the direction well, the directing property of the bit is destabilization and the tool face orientation will strenuously change. The mud motor sometimes will stall for this reason. This made the directional control become very difficult and the process waste a lot of time. Therefore researching relationship between the crown sketch and the cutting structure of the PDC bit and the tool face fluctuation is very important.The theory and feature of the PDC bit, such as crown sketch, hydraulics theory and cogging arranging are generalized in this paper systematically. The finite element analysis method are used the mechanical analysis of PDC bit drilling the direction well. The crown sketch which adapt the direction well drilling is defined, after several different crown sketch are researched used the finite element analysis method. The analysis result can help how to design cogging structure of oriented PDC bit. The fluid analysis of Several screw angle gauge protection are researched and the adaptable screw angle gauge protection are designed. According to the above-mentioned conclusion, one new oriented PDC bit are designed which will be used the direction well of Chang qing oil field. The bottom hole flow field of the new oriented PDC bit is optimized used the fluid analysis software.