主权项 |
1. A core lifter for use in a drilling system, the core lifter having a central axis, the core lifter comprising:
a tubular body comprising an exterior surface and an interior surface, the tubular body defining an elongate slot extending radially between the exterior surface and the interior surface and extending longitudinally relative to the central axis of the core lifter; a plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter, the plurality of longitudinally-oriented recesses extending radially inwardly relative to the central axis, wherein the plurality of longitudinally-oriented recesses do not extend radially through the tubular body between the exterior surface and the interior surface; and a plurality of tapered recesses formed in the interior surface of the tubular body of the core lifter, the plurality of tapered recesses extending radially outwardly and being tapered relative to the central axis, wherein the plurality of tapered recesses do not extend radially through the tubular body between the exterior surface and the interior surface, wherein the core lifter has a length, and wherein the plurality of longitudinally-oriented recesses formed in the exterior surface of the tubular body of the core lifter extend along at least 50 percent of the length of the core lifter relative to the central axis of the core lifter. |