Research On Main Geometric Parameters Of PDC Bit Influencing On The Mechanical Behavior

PDC bit was developed depending on the synthetic polycrystalline diamond compacts for cutting teeth during the 20th century. It can remarkably improve drilling efficiency. Moreover, because of its long working life, PDC bit obtained a wide range of use in geology, oil field drilling project. However, main geometric parameters influencing on its mechanical behavior were determined by experiments and empirical formulas in the past, and theory study documents on this aspect were rare. So carrying out theory research according to the main geometric parameters is quite necessary for providing optimization design with basis. The paper aiming at three wings inner sunken PDC bit and coring PDC bit did some researches.A thorough analysis on rock breaking mechanism due to steel PDC bit (including three wings inner sunken PDC bit and coring PDC bit) was performed, and the relation among geometry structure parameters of PDC bit was studied. The geometry basis equation of PDC bit was derived under the state of having no geometry hypothesis and geometry simplification; The mechanical properties of rock were analyzed, and investigation aiming at study of force analysis model between PDC tooth and rock was done. Besides, stress field was researched under the effect of two PDC single tooth; Motion law and working state of cutting teeth and any bit of them in the bottom were analyzed, and working state parameters of cutting teeth were determined; Involution of bit and circumferential reverse of bit part were discussed, and calculation model was simplified. Some work of analysis and calculation was done to working angle of cutting teeth. In addition, PDC bit cutting mechanics and so on were researched.The paper adopted CAD software Pro/E to build two typical three -dimensional entity model of PDC bit, and utilized data exchanging function of ANSYS and Pro/E in importing PDC bit model in ANSYS. Finite element analysis model on PDC bit was built, moreover, the research of numerical analysis aiming at the stress and displacement of model under the effect of static load was carried out. Variation regularity on main geometric parameters of PDC bit influencing on the mechanical behavior was acquired. On this basis, the paper did some optimization analysis due to main geometric Parameters of PDC bit, and obtained the best value range of main geometric parameters of PDC bit. Optimization results improved the mechanical behavior of PDC bit, and provided theory basis for design of PDC bit.