The invention discloses a micro-center PDC (
Polycrystalline Diamond Compact)
drill bit with a
conical tooth structure, which is characterized in that no PDC
cutting teeth are arranged in the central area of the
drill bit, a cylindrical groove is formed in the central area when the
drill bit rotates, a conical
diamond tooth is arranged at the bottom of the groove, and the axis of the conical
diamond tooth and the axis of the cylindrical groove are not in the same plane; the
discharge grooves pointed by the axes of the conical
diamond teeth are wider and deeper than other
discharge grooves, and the width of the
discharge grooves in the circumferential direction of the
drill bit is larger than the
diameter of the grooves. When the
drill bit drills in a hard stratum, a micro
rock core is formed, when the micro
rock core enters the groove and then makes contact with the conical diamond teeth arranged at the bottom of the groove, the micro
rock core is subjected to the radial force from the
conical teeth, the micro rock core is forced to be broken and enter the deep and wide large flow channel, and then the micro rock core enters the annular space of a well hole through the
chip groove, and the micro rock core and other common rock debris are discharged to the ground. Therefore, the micro rock core with the size much larger than that of common rock debris can be obtained on the ground, and the micro rock core can be used for geological
logging to identify rock information or strata.