| 摘要 |
The invention relates to a rock-destroying tool used for drilling oil and gas wells, particularly for drilling angled and horizontal wells and rocks represented by alternating interlayers of different hardness. The technical result consists in improving controllability whilst at the same time increasing the vibration-resistance of a PDC bit by using a special composite coating and adjusting the degree of protrusion of the cutter above this coating. The blade-type drill bit comprises a body with a connecting thread, a central channel and outlet openings for flushing liquid, and blades provided with polycrystalline diamond (PDC) cutters. The surface of the blades is equipped with a composite coating having a different degree of wear resistance over the thickness thereof, wherein the resistance of the composite coating to abrasive wear increases in the direction away from the outer surface towards the lower-lying layers, and the magnitude of the projection of the cutters close to the centre of the drill bit above the surface of the composite coating is less, as is known per se, than that required for drilling the most solid rocks in a given geological profile.
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