Rock breaking characteristics under different cutter arrangements on PDC bits
Polycrystalline diamond compact(PDC)bits have been widely used in drilling of soft to medium-hard rock forma-tions.A rational layout or arrangement of PDC cutters on the bits can significantly contribute to enhanced rock-breaking effi-ciency.In this study,a rock breaking experimental scheme of PDC cutters was designed for testing different cutter placement methods,and the characteristics and mechanisms of rock breaking of the PDC bits were investigated by measuring the cutting force,the shape and size of rock cuttings,the morphology of cutting grooves and the characteristics of rock micro-fragmenta-tion.The experimental results indicate that reasonable cutter height and cutter distribution density can reduce the specific en-ergy of rock-breaking and improve the rock breaking efficiency.The cutting depth can affect the distribution of microcracks on groove surface and the thickness of the microcracks layer at the bottom of the grooves.A boundary effect can be generated in a crack damage zone,which can effectively promote rock breaking.
PDC cuttercutter arrangementscutting groove spacingarea of cuttingrock breaking
万方数据
维普
