Micro-center PDC (polycrystalline diamond compact) bit with conical tooth structure

Abstract

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.

Description

technical field [0001] The invention relates to a diamond drill bit for petroleum and geological drilling, in particular to a micro-centered PDC drill bit with a bevel tooth structure. Background technique [0002] With the continuous improvement of the quality of diamond compacts, the application range of PDC drill bits in petroleum geological drilling is becoming wider and wider, and the speed and efficiency are playing an increasingly important role. In soft to medium hard formations, the footage and ROP are constantly increasing. However, the size of cuttings drilled by the PDC bit is small, which cannot meet the identification requirements of geological logging for formation rock information. In this case, the rock bit is generally used for drilling in the layer; The drill bit may whirl in the downhole, and the unstable work is prone to early damage to the cutting teeth. In hard formations, the PDC bit has less footage and has to replace the roller cone bit. However, t...

AI Technical Summary

Problems solved by technology

[0002] With the continuous improvement of the quality of diamond compacts, the application range of PDC drill bits in petroleum geological drilling is becoming wider and wider, and the speed and efficiency improvement play an increasingly important role. In soft to medium hard formations, the footage and ROP are constantly increasing. However, the size of the cuttings drilled by the PDC bit is small, which cannot meet the identification requirements of geological logging for formation rock information. The drill bit may whirl in the downhole, and the unstable work is prone to early damage to the cutting teeth. In hard formations, the PDC bit has less footage and has to replace the roller cone bit.

However, the roller cone bit has a slow drilling speed and a small footage, which is prone to the risk of cone loss

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