| 摘要 |
Core drill bits with extended matrix heights are described. The core drill bits have a series of slots or openings that are not located at the tip of the cutting portion and are therefore enclosed in the body of the matrix. The slots may be staggered and/or stepped throughout the matrix. As the matrix of the drill bit erodes through normal use, the fluid/debris notches at the tip of the bit are eliminated. As the erosion progresses, the slots become exposed and then they function at the proximal face of the bit as fluid/debris ways. This configuration allows the matrix height to be extended and lengthened without substantially reducing the structural integrity of the drill bit. With an extended matrix height, the drill bit can last longer and require less tripping in and out of the borehole to replace the drill bit.
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