HIGHLY-EFFICIENT COMPOSITE DRILL BIT FOR FORMATION DIFFICULT TO DRILL IN DEEP WELL

摘要

The present invention discloses a highly-efficient composite drill bit for aformation difficult to drill in a deep well, which comprises a drill bit body(1), bitcones (2) and nozzle anti-blocking mechanisms, wherein a fluid cavity (3) isformedinside the drill bit body (1); a crown portion (4) is arranged at the bottomof the drillbit body (1); a conical drill bit (5) is fixedly arranged on the bottomsurface of thecrown portion (4) and located in the center of the crown portion (4); aplurality ofnozzles (6) which are distributed around the conical drill bit (5) arearranged on thebottom surface of the crown portion (4), each nozzle (6) being communicatedwith thefluid cavity (3); a plurality of main blade wings (7) are fixedly arranged onthe bottomsurface of the crown portion (4) along the circumferential direction of thedrill bitbody (1); an auxiliary blade wing (8) is fixedly arranged between every twoadjacentmain blade wings (7). The present invention has the beneficial effects thatthestructure is compact, the rock breaking efficiency is improved, the servicelife of PDCcutting teeth is prolonged, nozzles can be prevented from being blocked byrocks ordebris, and the manufacturing cost is low.