Design and Study of PDC Bit for Igneous Rock Formation of Santanghu
Based on the geological configuration and formation lithology of igneous rock stratum of Santanghu, optimized design methods of PDC (polycrystalline diamond compact) bit are used to design PDC bit crown shape, cutting angle, the distribution of cutters and hydraulic structure, etc. Especially, these methods, which are design methods of gentle crown profile, spiral blade, high-density distribution of cutters, suitable back rake angle, and hydraulic structures which are more flexible nozzles of asymmetric arrangement and deeper fluid course layout, are fit for high hardness, multiple interbed and high abrasiveness of the igneous rock formation. The bit designed in this paper has turned out to be much better in the experiment of Horse 36 well of Santanghu.