| 摘要 |
<p>EARTH-BORING DRILL BITS WITH RECTANGULAR NOZZLES Earth-boring drill bits with one or more substantially rectangular nozzles through which drilling fluid is discharged to clean and cool the bit cutters and flush the cuttings produced by the bit from the drilling region to the top of the bore hole. The rectangular nozzle is more effective in cleaning and cooling the cutters and in removing the cuttings, when compared with the results achieved with the nozzle having a round or circular bore. The rectangular nozzle has a larger cross-sectional area than a circular nozzle while providing substantially the same fluid pressure drop across the nozzle, larger particles in the drilling fluid being capable of passing through the rectangular nozzle which would plug the passage through the circular nozzle. More specifically, rectangular nozzles are highly effective when incorporated in polycrystalline diamond compact bits, in which various cutter arrangements can be used,</p> |
